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Selected AbstractsComparison of the life history strategies of three Dysdercus true bugs (Heteroptera: Pyrrhocoridae), with special reference to their seasonal host plant useENTOMOLOGICAL SCIENCE, Issue 4 2005Katsuyuki KOHNO Abstract The life history strategy and seasonal host plant use of three Dysdercus bugs (D. cingulatus, D. poecilus and D. decussatus) were compared based on 2 years of twice monthly observations on Ishigaki-jima Island (24°N, 124°E) in the southernmost part of Japan. Dysdercus poecilus reproduced almost year round, exclusively on Sida rhombifolia, which bears fruit and/or seeds almost year round. Dysdercus cingulatus reproduced successively on various malvaceous and bombacaceous plant species, according to their seasonal fruiting cycles. Its robust reproduction was observed on Hibiscus makinoi during winter months and on Chorisia speciosa and Bombax ceiba in early summer, whereas small-scale reproduction was observed on various malvaceous plant species during the summer and autumn months. Dysdercus decussatus reproduced on Hibiscus tiliaceus and Thespesia populnea during the summer months, when these host plants bear abundant fruit and/or seeds, and its adults formed conspicuous aggregations without copulation on the underside of the leaves of those plants from November to the subsequent May. Each Dysdercus species showed a species-specific life history strategy according to the differences in the phenology of their host plants. [source] Hourly and daily clearness index and diffuse fraction at a tropical station, Ile-Ife, NigeriaINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 8 2009E. C. Okogbue Abstract Dataset consisting of hourly global and diffuse solar radiation measured over the period February 1992 and December 2002 have been utilized to investigate the diurnal and seasonal variations of hourly and daily clearness index together with the diffuse fraction at a tropical station Ile-Ife (7.5°N, 4.57°E), Nigeria. Statistical analysis (the frequency and cumulative frequency distribution of the hourly and daily clearness index) and subsequent characterization of the sky conditions over the station based on these were also done, and their implications for solar energy utilization in the area discussed. Daytime (11:00,15:00 LST) monthly mean hourly diffuse fraction, M,d (explained in a separate ,List of Symbols' provided, along with other symbols used in this article), have values, which are most of the time less than 0.52, 0.54 and 0.60 respectively for January, February and March in the dry season. However, during the months of July and August (which are typical of the wet season), the values range between 0.61 and 0.85 (being generally greater than 0.65) with the corresponding values of the monthly mean hourly clearness index, M,T, ranging between 0.23 and 0.45. Statistical analysis of hourly and daily clearness index showed that the local sky conditions at the station were almost devoid of clear skies and overcast skies (clear skies and overcast skies occurred for only about 3.5% and 4.8% of the time respectively). The sky conditions were rather predominantly cloudy (cloudy skies occurred for about 88% of the time) all the year round. Copyright © 2009 Royal Meteorological Society [source] Surface air temperature trends in Southern Brazil for 1960,2002INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2008Jose A. Marengo Abstract Trends in minimum and maximum air temperature and in the diurnal thermal range (DTR), and derived indices of extreme temperatures since the 1960's are assessed for southern Brazil. Most meteorological stations show steep increases in the night-time temperatures (depicted by the minimum temperature) as compared to slight increases in the daytime temperature (depicted by the maximum temperature), both year round and at the seasonal level. The warming trends are stronger during winter as compared to summer. Consequently, the observed annual and seasonal negative DTR trends in southern Brazil during the last 40 years are largely due to the greater increase in nighttime temperatures rather than daytime temperatures. At decadal timescales, the presence of more intense and frequent El Niño events during the last 20 years also contributes to warming and explains the steep increase in the air temperature extremes trends during this period, as compared to the relatively colder 1960,1980 period, especially for winter. Indices of temperature extremes defined using fixed limits for maximum and minimum temperatures for colder or warmer days were compared with percentile-based indices defined in the recent literature. The comparison shows that the frequency of warmer days increased during both summer and winter, especially during the last two decades. The observed positive tendencies in minimum temperatures and warmer days during winter occur even though extreme cold events and freezing conditions occurred in 1975, 1994 and 2000. Copyright © 2007 Royal Meteorological Society [source] Spatio-temporal climatic change of rainfall in East Java IndonesiaINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 4 2008Edvin Aldrian Abstract Spatial and temporal rainfall analysis of the Brantas Catchment Area (DAS Brantas), East Java, from 1955 to 2005 based on 40 rainfall stations with monthly rainfall data derived from daily rainfall data has been performed. To identify the climatic trend and annual changes in the area over the last five decades, we use the empirical orthogonal function (EOF) method based on multivariate statistics, followed by the fast Fourier transform (FFT) method for the power density spectrum analysis, the non-parametric Mann-Kendall trend test and the wavelet transform method. With EOF, we found the monsoonal rainfall pattern as the most dominant in this area, which explains about 72% of all variances. Without the annual signal, the leading EOF shows significant ENSO-modulated inter-annual and seasonal variabilities, especially during the second transitional period. We found a common and significant negative trend of accumulated rainfall and a negative trend of the monsoonal strength and dominance. This finding leads to changes in the annual pattern, which are increase in the ratio of rainfall during the wet season and increase of the dry spell period or the imbalance of the annual pattern. The increased ratio of the rainfall in the wet season has led to an increased threat of drought in the dry season and extreme weather in the wet season in recent decades. The role of the orographic effect had been detected from the decadal pattern, in which the high-altitude areas have greater rainfall amount all year round. From the decadal isohyets in December/January/February (DJF) and June/July/August (JJA), the rainfall amount decreased significantly during the last five decades as shown by a persistent increase of areas with low rainfall amount. By comparing the time series of rainfall data in two locations, the mountain and coastal areas, we discovered that the dry periods have increased, mainly in the low altitude area. Copyright © 2007 Royal Meteorological Society [source] Climate dynamics of atmosphere and ocean in the equatorial zone: a synthesisINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 13 2004Stefan Hastenrath Abstract A synopsis is offered of circulation mechanisms in the oceanic regions of the equatorial zone. Over the eastern Atlantic and Pacific, and especially in boreal summer, cross-equatorial flow from the Southern Hemisphere is strong and induces a tongue of cold surface waters, centred to the south of the equator. Upon crossing the equator in these sectors, owing to the Coriolis effect and a kinetic energy imbalance, the airstream speeds up and divergence develops, producing the Intertropical Divergence Zone (ITDZ). Once these processes result in the wind recurving from southeasterly to southwesterly, the flow slows down and becomes convergent, manifest in the Intertropical Convergence Zone, with a maximum to the south of the wind confluence. By contrast, over the western Atlantic and central Pacific and especially in boreal winter, winds in the equatorial band are predominantly from the east, upper-ocean Ekman transport is directed away from the equator, and the upwelling and cold tongue are centred on the equator. Cross-equatorial flow is insufficient to produce recurvature, the ITDZ is narrower and weaker, the divergence maximum is at the equator rather than in low northern latitudes, and the convergence maximum straddles the wind confluence. Over the Indian Ocean, the wind field is dominated by the alternation between the predominantly meridional flow of the winter and summer monsoons. Equatorial westerlies are limited to the short monsoon transition seasons. Essential for their origin is an eastward pressure gradient along the equator and weak southern trade winds, allowing recurvature somewhat south of the equator. Because the zonal pressure gradient is strongest in boreal summer and the southern trade winds are weakest in austral summer, the equatorial westerlies peak in spring and autumn. The boreal autumn equatorial westerlies are the surface manifestation of a powerful zonal,vertical circulation cell along the Indian Ocean equator. Equatorial zonal,vertical circulation cells require well-developed zonal flow in the lower troposphere along the equator and, therefore, appear confined to the oceanic longitudes and certain seasons. Thus, they are found over the Atlantic only in boreal winter and over the Indian Ocean only in boreal autumn, whereas over the Pacific they prevail all year round. Copyright © 2004 Royal Meteorological Society [source] Intrabasin variations in age and growth of Barbus bocagei populationsJOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2002J. M. Oliveira The age and growth of the Iberian cyprinid Barbus bocagei Steindachner 1865, were studied in six different streams in the River Tagus basin. The fish were aged by scale reading and their lengths were back-calculated. Age structures were similar at four sites (R. Ocreza, R. Rio Frio, R. Sever and R. Canha), where six to seven age classes were present. In contrast, 10 age groups were detected in the R. Erges and 11 in the R. Nabão. The slopes (b) of the length,weight regressions did not differ significantly between the six populations. The growth of the populations was compared with that available throughout the study area (another two sites). Classification analysis of the lengths-at-age by sites matrix revealed three major groups (by decreasing order of growth rate): 1, Belver Reservoir; 2, R. Tagus, Nabão and Erges; 3, Rio Frio, Sever, Canha and Ocreza. We hypothesize that highly stressful conditions in the summer diminish growth rates and longevity in the Rio Frio, Canha and Ocreza rivers and that lower temperatures all year round could limit growth in the Sever. Higher growth rates were observed in warm-water streams with more stable environmental conditions (group 2) and in a highly productive lentic system (group 1). Among the sites that were studied, the one that revealed the highest growth performance by B. bocagei was the most polluted, the R. Nabão. This offers evidence of the species plasticity and of its successful adaptation to streams displaying significant degradation in water quality. [source] High individual repeatability and population differentiation in stable isotope ratios in winter-grown collared flycatcher Ficedula albicollis feathersJOURNAL OF AVIAN BIOLOGY, Issue 2 2009Mårten B. Hjernquist For migrants, we often lack complete information of their spatial distribution year round. Here, we used stable carbon, nitrogen and hydrogen isotope ratios extracted from feathers grown at the wintering sites of the long-distance migratory collared flycatcher Ficedula albicollis, to study how individuals from different breeding populations are distributed at the wintering sites. A sub-sample of birds was also sampled in two consecutive years to test for the repeatability of isotope ratios. Birds from the same breeding populations had more similar isotope ratios compared to birds from other nearby populations (10,100 km apart). Furthermore, isotope repeatability within individuals was high, implying that the observed pattern of isotope variation is consistent between years. We put forward two hypotheses for these patterns; 1) strong wintering site philopatry and migratory connectivity, suggesting that migratory connectivity may potentially be found on a much smaller spatial scale than previously considered, and 2) consistent interpopulation differentiation of feeding ecology at their wintering site. [source] Competition between domestic dogs and Ethiopian wolf (Canis simensis) in the Bale Mountains National Park, EthiopiaAFRICAN JOURNAL OF ECOLOGY, Issue 2 2010A. Atickem Abstract The potential effects of the domestic dogs (Canis familiaris) on the Endangered Ethiopian wolf (Canis simensis) through exploitative and interference competition were studied in the Web Valley of Bale Mountains national park between November 2001 and February 2003. All dogs were owned in the study area and no feral dogs were reported or observed during the research period. The diet of domestic dogs was dominated by barley husks and human faeces which contributed 45% and 20.7% of the total 382 meals observed during focal watch observations. Analysis of dog faeces provided similar results with barley husks, human faeces and animal carcasses occurring in 86.8%, 21.4% and 19.4% of the 1200 faecal samples analysed. Both focal watch and faecal analyses revealed that rodents contributed only a very small proportion of the diet of dogs accounting for only 4.2% of the focal watch and 2.8% of the faecal analysis of roaming dogs. As Ethiopian wolves fed almost exclusively on rodent year round, no significant exploitative competition between dogs and wolves were assessed. Only small proportion of the domestic dogs roamed in the Ethiopian wolf range and interference competition did not appear to be a serious threat for the Ethiopian wolf. Résumé De novembre 2001 à février 2003, on a étudié les effets potentiels des chiens domestiques (Canis familiaris) sur le loup d'Ethiopie (Canis simensis) qui est en danger, en raison d'une compétition par exploitation alimentaire ou par interférences, dans la Vallée de Web, dans le Parc National des montagnes de Bale. Tous les chiens de l'étude avaient un propriétaire, et nous n'avons ni rapporté ni observé de chien féral pendant cette période. Le régime alimentaire des chiens comprenait principalement de la balle d'orge et des excréments humains qui composaient respectivement 45% et 20,7% du total des 382 repas observés pendant des observations focalisées. L'analyse des excréments de chiens donne des résultats semblables : la balle d'orge, les excréments humains et les carcasses d'animaux sont présents dans 86,8%, 21,4% et 19,4% des 1 200 échantillons fécaux analysés. Et les observations focalisées et les analyses des crottes ont révélé que les rongeurs ne composent qu'une toute petite proportion du régime des chiens, avec 4,2% des observations et 2,8% des analyses fécales des chiens errant en liberté. Comme les loups d'Ethiopie se nourrissent toute l'année presque exclusivement de rongeurs, nous avons estimé qu'il n'y avait aucune compétition par exploitation significative entre les chiens et les loups. Seule une petite proportion de chiens circulent dans l'aire de distribution du loup d'Ethiopie, et la compétition par interférence a semblé ne pas constituer une menace sérieuse pour le loup d'Ethiopie. [source] Dietary specialization and climatic-linked variations in extant populations of Ethiopian wolvesAFRICAN JOURNAL OF ECOLOGY, Issue 2 2010Jorgelina Marino Abstract Understanding of the biology of rarity is central to the conservation of some endangered species. Rare taxa are often reported to be specialized, but they are usually poorly studied. The Ethiopian wolf (Canis simensis) is endemic to the Ethiopian highlands and in two major populations, Bale and Arsi in the southern range of the species, it preys almost exclusively upon diurnal rodents all year round, mainly molerats Tachyoryctes macrocephalus and common molerats T. splendens, respectively. Where these large rodents are absent or rare, wolves are expected to rely more heavily on nocturnal rats or livestock. Prey remains in 161 scats from five newly studied populations confirmed that wolves are indeed specialist rodent hunters elsewhere, and that their narrow diets are dominated by diurnal Murinae rats (60,83% of prey occurrences). Swamp rats Otomys typus were the main prey, followed by grass rats Arvicanthis abyssinicus. Common molerats, Lophuromys rats and nocturnal Stenocephalemys spp. constituted the variable portion of the diets, and their proportional contributions varied across populations in relation to elevation and latitude. Towards the north, where the climate is drier and human populations more dense, wolves predate more frequently on rat-sized prey, including nocturnal species, with implications for the survival of small populations in the Northern Highlands. Résumé Pour la conservation de certaines espèces en danger, il est essentiel de bien comprendre la biologie de la rareté. On rapporte souvent que des taxons rares sont spécialisés, mais ils sont généralement peu étudiés. Le loup d'Ethiopie Canis simensis est endémique des hauts plateaux éthiopiens et deux populations majeures, Bale et Arsi, dans la partie sud de leur aire de répartition, se nourrissent toute l'année presque exclusivement de petits rongeurs diurnes, surtout des rats-taupes géants Tachyoryctes macrocephalus et, plus communs, des rats taupes des montagnes T. splendens. Là où ces rongeurs sont absents ou rares, on s'attend à ce que les loups se nourrissent davantage de rats nocturnes ou de bétail. Des restes de proies identifiées dans 161 crottes de cinq nouvelles populations étudiées récemment ont confirmé que les loups sont bien, ailleurs, des chasseurs spécialisés en rongeurs et que leur régime alimentaire peu varié est dominé par des Murinae diurnes (60,83% des proies observées). Les rats des marais Otomys typusétaient les proies principales, suivis par les rats des herbes Arvicanthis abyssinicus. Les rats-taupes communs, les rats Lophuromys et les nocturnes Stenocephalemys spp. constituaient des portions variables du menu, et la proportion de leur contribution variait pour les populations en fonction de l'elevation et de la latitude. Vers le nord, là où le climat est plus sec et où la population humaine est plus dense, les loups s'attaquent plus souvent à des proies de la taille des rats, y compris des espèces nocturnes, ce qui a des implications pour la survie des petites populations des hauts plateaux du nord. [source] Coevolution between crossbills and black pine: the importance of competitors, forest area and resource stabilityJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 5 2009C. W. BENKMAN Abstract Studies of predator-prey interactions have found that geographically structured coevolution has played an important role in the adaptive diversification of crossbills (Loxia spp.). We extend those studies by considering common crossbills (L. curvirostra) in the Mediterranean where they rely on seeds in the cones of black pine (Pinus nigra). On the continent, where tree squirrels (Sciurus vulgaris) are present, enhanced defenses against crossbills were most evident in larger areas of pine forest. On islands in the absence of tree squirrels, crossbills and black pine have coevolved in a predator-prey arms race on Cyprus but not Corsica. In contrast to other conifers that island endemic crossbills rely upon, black pine does not hold seeds in its cones year round. Consequently, key to the strong crossbill,pine interaction on Cyprus is likely the presence of an alternative conifer that provides seeds during early summer when black pine seeds are scarce. [source] Population structure, age and growth of macrourid fish from the upper slope of the Eastern-Central MediterraneanJOURNAL OF FISH BIOLOGY, Issue 5 2000G. D'Onghia Hymenocephalus italicus, Nezumia sclerorhynchus and Coelorhynchus coelorhynchus were found in 80, 75 and 69% of trawl hauls carried out between 250 and 750 m on the upper slope of the Ionian Sea. The abundance of H. italicus and N. sclerorhynchus increased with depth while in C. coelorhynchus the highest densities were observed in the uppermost 500 m. In all three grenadiers the average size increased with depth. The populations had a multimodal sizefrequency distribution. In H. italicus adults were generally more represented in the population and the abundance of juveniles varied with seasons. In N. sclerorhynchus and mostly in C. coelorhynchus the bulk of the population was generally made up of small individuals the year round. In N. sclerorhynchus a seasonal pattern was shown in the depth distribution of juveniles. The sex ratio was in favour of females in larger specimens and in each bathymetric stratum. Seasonal growth was detected in the otoliths of the three species. Maximum ages were around 9 years in H. italicus and N. sclerorhynchus; 8 years in C. coelorhynchus. Although some differences have been detected in the population ecology of the three species, they are characterized by a prolonged recruitment during the year, slow growth, longevity and delayed maturity. [source] NATURAL CHEDDAR CHEESE TEXTURE VARIATION AS A RESULT OF MILK SEASONALITYJOURNAL OF TEXTURE STUDIES, Issue 1 2003ANDREW L. HALMOS ABSTRACT A set of standard testing conditions using the TA-XT2 Texture Analyser were established to monitor cheddar cheese texture variation. Cheddar cheese was produced in the standard commercial practice and sampled at monthly intervals throughout the milk production season (August - June), and monitored for textural and compositional changes occurring during ripening. The composition, based on fat and protein levels, of the cheese was relatively constant during the period, which was expected as the commercial process aims for that outcome. A reduction in the force and degree of compression at fracture with time, indicative of a reduction in cheese firmness and an increase in cheese crumbliness, was recorded as the milk production season progressed. The degree of proteolysis and changes in milk fat in late season milk are primarily responsible for the changes recorded in cheese texture. The differences observed between cheeses produced at different times during the season indicate that the current fat and protein standardization employed by cheese-makers is not adequate to provide cheddar cheese with consistent textural characteristics year round. [source] Seasonal changes of CLA isomers and other fatty acids of milk fat from grazing dairy herds in the AzoresJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2008Oldemiro A Rego Abstract BACKGROUND: Season of the year associated with dietary changes has been recognized as a factor implicated in milk fat fatty acid (FA) profile in dairy cows. However, a lack of information exists concerning cows grazing all year round as is practiced in the Azores, where cows are supplemented in winter with maize silage plus concentrates, while in spring the higher grass allowance only requires supplementation with concentrate. The main objective of this study was to detect any seasonal variation of FA profile of milk fat from milk sampled in bulk tanks of 12 Azorean dairy herds. RESULTS Compared to winter milk, milk fat from spring presented a higher proportion of CLA cis -9,trans -11 (14.3 versus 9.6 g kg,1 FA), C18:1 trans -11 (32 versus 22 g kg,1 FA), C18:2 trans -11,cis -15 (3.7 versus 2.2 g kg,1 FA), CLA trans -11,cis -13 (0.34 versus 0.23 g kg,1 FA) and C18:3 n-3 (5.7 versus 5.4 g kg,1 FA). The C18:2 n-6/C18:3 n-3 ratio was lower (P < 0.05) in spring. Branched-chain FA, except the anteiso -C15:0, were higher in spring, while odd-chain FA (C15:0) were higher in winter. CONCLUSION: Dairy herd management in the Azores presents a seasonal variation of milk fat FA composition, where the spring milk may present increased potential benefits for human consumers. Copyright © 2008 Society of Chemical Industry [source] Seasonal effects and fine-scale population dynamics of Aedes taeniorhynchus, a major disease vector in the Galapagos IslandsMOLECULAR ECOLOGY, Issue 20 2010ARNAUD BATAILLE Abstract Characterization of the fine-scale population dynamics of the mosquito Aedes taeniorhynchus is needed to improve our understanding of its role as a disease vector in the Galapagos Islands. We used microsatellite data to assess the genetic structure of coastal and highland mosquito populations and patterns of gene flow between the two habitats through time on Santa Cruz Island. In addition, we assessed possible associations of mosquito abundance and genetic diversity with environmental variables. The coastal and highland mosquito populations were highly differentiated from each other all year round, with some gene flow detected only during periods of increased precipitation. The results support the hypothesis that selection arising from ecological differences between habitats is driving adaptation and divergence in A. taeniorhynchus, and maintaining long-term genetic differentiation of the populations against gene flow. The highland and lowland populations may constitute an example of incipient speciation in progress. Highland populations were characterized by lower observed heterozygosity and allelic richness, suggesting a founder effect and/or lower breeding site availability in the highlands. A lack of reduction in genetic diversity over time in highland populations suggests that they survive dry periods as dormant eggs. Association between mosquito abundance and precipitation was strong in the highlands, whereas tide height was the main factor affecting mosquito abundance on the coast. Our findings suggests differences in the infection dynamics of mosquito-borne parasites in the highlands compared to the coast, and a higher risk of mosquito-driven disease spread across these habitats during periods of increased precipitation. [source] Sunlight robbery: A critique of public health policy on vitamin D in the UKMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 8 2010Oliver GillieArticle first published online: 28 JUN 2010 Abstract The British Isles have a very cloudy climate and as a result receive fewer hours of clear sunlight than most other industrial regions. The majority of people in these islands have low blood levels of vitamin D [25(OH)D] all year round. Few food products are fortified with vitamin D in the UK and the government does not recommend any vitamin D supplement for most adults in the UK. Diseases associated with vitamin D insufficiency such as cancer, heart disease, diabetes (types 1 and 2) and multiple sclerosis are more frequent in the UK, and particularly in Scotland, than in many other European countries and some, such as multiple sclerosis and diabetes (types 1 and 2), are increasing in incidence. Present knowledge suggests that the risk of some chronic diseases could be reduced if vitamin D intake or sun exposure of the population were increased. Yet policy and public health recommendations of the UK government and its agencies (e.g. the Health Protection Agency, the Food Standards Agency) and of Cancer Research UK have failed to take full account of established and putative benefits of vitamin D and/or sunshine. The epidemic of chronic disease in the UK, which is associated with and caused at least in part by vitamin D insufficiency, has not been adequately recognized by these agencies, and too often measures taken by them have been misguided, inappropriate or ineffective. [source] Ecological physiology of Pereskia guamacho, a cactus with leavesPLANT CELL & ENVIRONMENT, Issue 2 2006ERIKA J. EDWARDS ABSTRACT The specialized physiology of leafless, stem-succulent cacti is relatively well understood. This is not true, however, for Pereskia (Cactaceae), the 17 species of leafy trees and shrubs that represent the earliest diverging lineages of the cacti. Here we report on the water relations and photosynthesis of Pereskia guamacho, a small tree of the semiarid scrubland of Venezuela's Caribbean coast. Sapwood-specific xylem conductivity (Ksp) is low when compared to other vessel-bearing trees of tropical dry systems, but leaf-specific xylem conductivity is relatively high due to the high Huber value afforded by P. guamacho's short shoot architecture. P. guamacho xylem is not particularly vulnerable to drought-induced cavitation, especially considering the high leaf water potentials maintained year round. This is confirmed by the lack of significant variation exhibited in Ksp between wet and dry seasons. In the rainy season, P. guamacho exhibited C3 -like patterns of stomatal conductance, but during a prolonged drought we documented nocturnal stomatal opening with a concomitant accumulation of titratable acid in leaves. This suggests that P. guamacho can perform drought-induced crassulacean acid metabolism (CAM photosynthesis), although ,13C values imply that most carbon is assimilated via the C3 pathway. P. guamacho leaves display very low stomatal densities, and maximum stomatal conductance is low whether stomata open during the day or night. We conclude that leaf performance is not limited by stem hydraulic capacity in this species, and that water use is conservative and tightly regulated at the leaf level. [source] Shallow-water habitats as sources of fallback foods for homininsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Richard Wrangham Abstract Underground storage organs (USOs) have been proposed as critical fallback foods for early hominins in savanna, but there has been little discussion as to which habitats would have been important sources of USOs. USOs consumed by hominins could have included both underwater and underground storage organs, i.e., from both aquatic and terrestrial habitats. Shallow aquatic habitats tend to offer high plant growth rates, high USO densities, and relatively continuous USO availability throughout the year. Baboons in the Okavango delta use aquatic USOs as a fallback food, and aquatic or semiaquatic USOs support high-density human populations in various parts of the world. As expected given fossilization requisites, the African early- to mid-Pleistocene shows an association of Homo and Paranthropus fossils with shallow-water and flooded habitats where high densities of plant-bearing USOs are likely to have occurred. Given that early hominins in the tropics lived in relatively dry habitats, while others occupied temperate latitudes, ripe, fleshy fruits of the type preferred by African apes would not normally have been available year round. We therefore suggest that water-associated USOs were likely to have been key fallback foods, and that dry-season access to aquatic habitats would have been an important predictor of hominin home range quality. This study differs from traditional savanna chimpanzee models of hominin origins by proposing that access to aquatic habitats was a necessary condition for adaptation to savanna habitats. It also raises the possibility that harvesting efficiency in shallow water promoted adaptations for habitual bipedality in early hominins. Am J Phys Anthropol 140:630,642, 2009. © 2009 Wiley-Liss, Inc. [source] Patterns of reproduction in Malayan silvered leaf monkeys at the Bronx ZooAMERICAN JOURNAL OF PRIMATOLOGY, Issue 10 2009Nichole Shelmidine Abstract Within phylogenetic limits reproductive characteristics of a given species may vary between populations in response to ecological and social factors. For instance, in environments where high quality nutrition is readily available, the onset and speed of reproduction are often accelerated. Other influencing factors might be maternal experience or the sex of the infant. Here we present data on reproductive characteristics for the silvered leaf monkey (Trachypithecus cristatus), a medium-sized Asian colobine housed at the Wildlife Conservation Society's Bronx Zoo as a one-male group. To place the species into an appropriate phylogenetic context, we limited our comparison to other colobine species. Demographic data span 21.4 years (October 1985 to March 2007) and derive from 30 adult females (128.0 female years). Detailed behavioral data stem from a 2.2 years study (November 2002 to January 2005; 734 days, 4,225,hr). As in other Asian colobines, receptive periods were short (mean=4.3 days, n=68). This is expected for one-male groups where receptivity likely indicates, rather than conceals, ovulation. Gestation length was estimated based on a change in the pattern of sexual behavior (mean=194.6 days, n=7). It fell within the range reported for the taxon. Births occurred year round, at an early age (mean=2.9 years, n=8), at short intervals (mean=14.9 months, n=59) in combination with a short lactation (mean 12.1 months, n=9) likely due to the nearly unlimited availability of nutrition in this zoo setting. Primiparous females tended to have a longer first interbirth interval but infant survival rates were similar to multipara possibly due to the absence of predators. Maternal investment was independent of the infant's sex and birth sex ratio was even. Our results emphasize that when interpreted with caution, zoo populations yield realistic reproductive characteristics that can help fill the gap in our knowledge about colobine life history. Am. J. Primatol. 71:852,859, 2009. © 2009 Wiley-Liss, Inc. [source] The effects of infant births on male,female relationships in Cebus capucinusAMERICAN JOURNAL OF PRIMATOLOGY, Issue 5 2009Claire R. Sheller Abstract Most primates are characterized by cohesive male,female bonds that are maintained year round. While recent studies have addressed the selective pressures influencing the evolution of male,female relationships in primates, we know relatively little about the proximate mechanisms affecting them. It has been demonstrated that newborn white-faced capuchins (Cebus capucinus) attract the attention of other group members and this may be an important mechanism influencing male,female relationships. We studied two groups of C. capucinus in the Area de Conservación Guanacaste, Costa Rica, between February and July 2007. A total of 348 hr of focal data were collected on all adult males (n=6) residing in each of the study groups. During our study, 13 of the 14 group females were either pregnant or lactating, and 9 infants were born. We calculated an average daily affiliation rate between all group males combined and each adult female four weeks before and four weeks after the birth of her infant. Repeated measures ANOVAs revealed no significant changes in affiliation following infant births (F=2.262, df=1, P<0.176). Results remained nonsignificant for rank (F=1.550, df=1, P<0.260) and group membership (F=0.729, df=1, P<0.429). Infant sex was the only variable with a significant effect on affiliation rates between males and females (F=10.020, df=1, P<0.019). Adult males increased their affiliation with all adult females that gave birth to male infants (n=4), while their rates decreased with all but one of the adult females with female infants (n=4). While preliminary, these results indicate that the adult males may cultivate relationships with other males at a young age. Am. J. Primatol. 71:380,383, 2009. © 2009 Wiley-Liss, Inc. [source] Activity budgets and activity rhythms in red ruffed lemurs (Varecia rubra) on the Masoala Peninsula, Madagascar: seasonality and reproductive energeticsAMERICAN JOURNAL OF PRIMATOLOGY, Issue 1 2005Natalie Vasey Abstract The activity budgets and daily activity rhythms of Varecia rubra were examined over an annual cycle according to season and reproductive stage. Given the relatively high reproductive costs and patchy food resources of this species, I predicted that V. rubra would 1) travel less and feed more during seasonal resource scarcity in an attempt to maintain energy balance, and 2) show sex differences in activity budgets due to differing reproductive investment. Contrary to the first prediction, V. rubra does not increase feeding time during seasonal food scarcity; rather, females feed for a consistent amount of time in every season, whereas males feed most during the resource-rich, hot dry season. The results are consistent with other predictions: V. rubra travels less in the resource-scarce cold rainy season, and there are some pronounced sex differences, with females feeding more and resting less than males in every season and in every reproductive stage except gestation. However, there are also some provocative similarities between the sexes when activity budgets are examined by reproductive stage. During gestation, female and male activity budgets do not differ and appear geared toward energy accumulation: both sexes feed and rest extensively and travel least during this stage. During lactation, activity budgets are geared toward high energy expenditure: both sexes travel most and in equal measure, and rest least, although it remains the case that females feed more and rest less than males. These similarities between female and male activity budgets appear related to cooperative infant care. The high energetic costs of reproduction in V. rubra females may require that they allot more time to feeding year round, and that their overall activity budget be more directly responsive to seasonal climate change, seasonal food distribution, and reproductive schedules. Am. J. Primatol. 66:23,44, 2005. [source] A Two Year Follow-Up Study of Common Virus Infections in Hemodialysis Patients in TaiwanARTIFICIAL ORGANS, Issue 10 2002Tze Wah Kao Abstract: The study was designed to determine whether hemodialysis patients in Taiwan had a different antibody response to common virus infections compared to the normal population. Serum samples from 18 hemodialysis patients and 21 healthy volunteers were obtained every 3 months for 2 years. Geometric mean titers (GMTs) of immunoglobulin G (IgG) antibodies to cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), as well as Type A and Type B influenza viruses (Inf. A, Inf. B) were compared between the patient and the control groups. The prevalence rates and the rates of recurrent infection were similar in both groups. However, the patient group had a higher percentage of persons having persistent EBV and CMV infections (p < 0.05) and also higher GMTs of antibodies nearly the whole year round, especially significant in September and December (p < 0.05). In patients with hepatitis C, their GMTs of EBV, VZV, Inf. A, and Inf. B were higher than those without (p < 0.05). [source] A retrospective report of 90 dogs with suspected cane toad (Bufo marinus) toxicityAUSTRALIAN VETERINARY JOURNAL, Issue 10 2004MP REEVES Objective To report the clinical characteristics of toad toxicity in domestic dogs in Brisbane. Design A retrospective analysis of clinical cases. Procedure All cases of toad poisoning which presented to a northern suburbs emergency clinic in Brisbane over a 30-month period beginning in April 1999 were reviewed. Results A total of 90 canine cases of suspected toad poisoning were reviewed. Small breed dogs accounted for 76% of cases. Jack Russell, Silky, and Fox Terriers were the most represented breeds. Cases were reported year round, with fewest cases over the winter months. The most common clinical signs were increased salivation (78% of cases), and red oral mucous membranes (63% cases). Seizures occurred in 31% of cases. Generally the outcome was excellent with 96% survival. [source] Quantification of group 5 grass pollen allergens in house dustCLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2000B. Fahlbusch Background It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. However, it is of virtual importance for grass pollen allergic patients with symptoms all the year round to know the concentration of grass pollen allergens in their homes. Objective The main objective of this study was to quantify the amount of grass pollen allergen in mass units (,g Phl p 5) in dust settled indoors and to detect the distribution of allergenic activity in different sampling locations of homes. Furthermore, we studied the seasonal fluctuation of allergen content in dust samples. Methods We adapted the two site binding assay for detection of group 5 grass pollen allergens in samples from randomly selected homes in Hamburg (n = 371), Erfurt (n = 396), Hettstedt (n = 353), Zerbst (n = 289) and Bitterfeld (n = 226), Germany. Dust samples were collected from floor of living room (LR), bedroom (BR) or children's room (CR) and mattress (MA) during period of June 1995 to August 1998. The amount of the major grass group 5 allergens was detected in ,g/g dust. Results Phl p 5 was detected in 67% of the samples analysed (n = 4760). The range was between undetectable (< 0.03 ,g/g dust) and 81 ,g/g dust. Phl p 5 levels were significantly higher in the dust from LR (geometric mean 0.117 ,g/g dust) or BR/CR floors (geometric mean 0.098 ,g/g dust) than in mattresses (geometric mean 0.043 ,g/g dust). We observed seasonal fluctuation of indoor Phl p 5 levels with peak in June but also annual differences. Thus Phl p 5 content indoors reflects also the different quantities of pollen counts of annual courses. During pollination period we found two times higher Phl p 5 levels (0.172 ,g/g dust, P < 0.001) than outside of grass pollination season (0.095 ,g/g dust). The indoor Phl p 5 levels outside of season seem to be independent of pollination before. We suppose that settled pollen grains or allergenic material from outdoor particles carried indoors via footwear and clothes accumulates in house dust. Conclusion Although we not known how the allergens in settled dust are equilibrated with those in the air, the considerable high level of Phl p 5 in indoor dust even during periods when no grass pollen is present in the atmosphere may be an important cause of pollen-allergy symptoms outside of season. [source] Salmonella Enteritidis in Bosnia and HerzegovinaCLINICAL MICROBIOLOGY AND INFECTION, Issue 11 2004S. Uzunovic-Kamberovic Abstract A comprehensive retrospective analysis of human Salmonella Enteritidis isolates in the Zenica-Doboj Canton of Bosnia and Herzegovina was conducted by inquiry and questionnaire. In the period 1998,2000, 299 isolates of Salmonella spp. were recorded, of which S. Enteritidis accounted for 74.2%. The isolation rate of S. Enteritidis increased during this period, from 12.7 to 25.5 isolates/year/100 000 population. Isolates were obtained all year round, mostly from sporadic cases of infection or limited family outbreaks. Home-made food was identified as the most important source of infection, being implicated in 81% of outbreaks and 81.7% of cases of sporadic infection. [source] | |||||||||||||||||||