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Direct Cause (direct + cause)
Selected AbstractsClimate Variability in Regions of Amphibian DeclinesCONSERVATION BIOLOGY, Issue 4 2001Michael A. Alexander The reanalysis system merges observations from airplanes, land stations, satellites, ships, and weather balloons with output from a weather-forecast model to create global fields of atmospheric variables. Station data consisted of temperature and precipitation measured with thermometers and rain gauges at fixed locations. Temperatures were near normal in Colorado when the amphibian declines occurred in the 1970s, whereas in Central America temperatures were warmer than normal, especially during the dry season. The station data from Puerto Rico and Australia indicated that temperatures were above normal during the period of amphibian declines, but reanalysis did not show such a clear temperature signal. Although declines occurred while the temperature and precipitation anomalies in some of the regions were large and of extended duration, the anomalies were not beyond the range of normal variability. Thus, unusual climate, as measured by regional estimates of temperature and precipitation, is unlikely to be the direct cause of amphibian declines, but it may have indirectly contributed to them. Previous researchers have noted that the declines appear to have propagated from northwest to southeast from Costa Rica to Panama and from southeast to northwest in Queensland, Australia. Wind has the potential to transport pathogens that cause amphibian mortality. The mean direction of the near-surface winds tended to parallel the path of amphibian declines from July,October in Central America and from May,July in Australia. The wind direction was highly variable, however, and the propagation rate of amphibian declines was much slower than the mean wind speed. In addition, the most likely pathogen is a chytrid fungus that does not produce desiccation-resistant spores. Thus, if wind is involved in the propagation of amphibian declines, it is through a complex set of processes. Resumen: Exploramos la relación entre las declinaciones de anfibios y las variaciones climáticas en Colorado, E.U.A., Puerto Rico, Costa Rica/Panamá y Queensland, Australia por medio de dos fuentes de información: resultados "sistema de reanálisis" del Centro Nacional de Predicción Ambiental y datos de estaciones área-promedio. El sistema de reanálisis combina observaciones de aeroplanos, estaciones terrestres, satélites, barcos y globos climatológicos, con resultados de un modelo de predicción climatológica para crear campos globales de variables atmosféricas. Los datos de estaciones fueron de temperatura y precipitación medidos con termómetros y pluviómetros en localidades fijas. Las temperaturas fueron casi normales en Colorado cuando ocurrieron las declinaciones en la década de 1970, mientras que las temperaturas en Centro América fueron mayores a lo normal, especialmente durante la época de sequía. Los datos de estaciones en Puerto Rico y Australia indicaron que la temperatura fue mayor a la normal durante el período de declinación de anfibios, pero un nuevo análisis no mostró una señal de temperatura tan clara. Aunque las declinaciones ocurrieron mientras las anomalías de temperatura y precipitación fueron grandes y de duración prolongada en algunas de las regiones, las anomalías no rebasaron el rango de variabilidad normal. Por lo tanto, es poco probable que el clima inusual, medido por estimaciones regionales de temperatura y precipitación, sea la causa directa de las declinaciones de anfibios, pero pudo haber contribuido indirectamente a ellas. Investigaciones previas notan que las declinaciones parecen haberse propagado de noroeste a sureste de Costa Rica a Panamá y de sureste a noreste en Queensland, Australia. El viento tiene el potencial de transportar patógenos que causan mortalidad de anfibios. La dirección promedio de los vientos superficiales tendió a ser paralela al camino de las declinaciones de anfibios de julio a octubre en Centro América y de mayo a julio en Australia. Sin embargo, la dirección del viento fue altamente variable y la tasa de propagación de declinaciones de anfibios fue mucho más lenta que la velocidad promedio del viento. Adicionalmente, el patógeno más probable es un hongo quítrido que no produce esporas resistentes a la desecación. Por tanto, si el viento está implicado en la propagación de declinaciones de anfibios, lo es por medio de un complejo conjunto de procesos. [source] Graft rejection and hyperacute graft-versus-host disease in stem cell transplantation from non-inherited maternal antigen complementary HLA-mismatched siblingsEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 2 2007Hirokazu Okumura Abstract Human leukocyte antigen (HLA)-mismatched stem cell transplantation from non-inherited maternal antigen (NIMA)-complementary donors is known to produce stable engraftment without inducing severe graft-versus-host disease (GVHD). We treated two patients with acute myeloid leukemia (AML) and one patient with severe aplastic anemia (SAA) with HLA-mismatched stem cell transplantation (SCT) from NIMA-complementary donors (NIMA-mismatched SCT). The presence of donor and recipient-derived blood cells in the peripheral blood of recipient (donor microchimerism) and donor was documented respectively by amplifying NIMA-derived DNA in two of the three patients. Graft rejection occurred in the SAA patient who was conditioned with a fludarabine-based regimen. Grade III and grade IV acute GVHD developed in patients with AML on day 8 and day 11 respectively, and became a direct cause of death in one patient. The findings suggest that intensive conditioning and immunosuppression after stem cell transplantation are needed in NIMA-mismatched SCT even if donor and recipient microchimerisms is detectable in the donor and recipient before SCT. [source] Atmospheric circulation patterns related to heavy snowfall days in Andorra, PyreneesINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2005Pere Esteban Abstract Heavy snowfalls over mountain regions are often a direct cause of avalanches. Specific synoptic-scale atmospheric situations are responsible for these kinds of extreme snowfall event, and this is indeed the case for Andorra, a small country located in the Pyrenees, between France and Spain. Based on days with an intensity of at least 30 cm of snow in a 24 h period, the present study uses principal component analysis (PCA) and clustering techniques to characterize the synoptic circulation patterns for these days during the winter season. The area of analysis encompasses the region 30,60°N by 30°W,15°E and the period covers the winter seasons from 1986,87 to 2000,01. The methodology proposed involves a preprocessing approach consisting of a spatial standardization of the data used for the PCA, an alternative approximation to decide the centroids and the number of groups for the K -means clustering, and the rejection of the iterations for this algorithm. This approach enables the synoptic classification of every heavy snowfall day, and composite maps were constructed for sea-level pressure, 500 hPa geopotential height, and 1000,500 m thickness (the 5270 m, 5400 m and 5520 m contour lines). The results show seven circulation patterns, most of them with an Atlantic component of the wind, and others with a clear Mediterranean advection that could be combined with cold continental air. The results, as weather charts, could be a useful tool to assist meteorological models in heavy snowfall forecasting, and the day's classification obtained opens up future possibilities for detailed meteorological and climatological analysis of the established types. Copyright © 2005 Royal Meteorological Society [source] Case study of a one-sided attack by multiple troop members on a nontroop adolescent male and the death of Japanese macaques (Macaca fuscata)AGGRESSIVE BEHAVIOR, Issue 4 2009Masaki Shimada Abstract An adolescent wild male Japanese macaque (Macaca fuscata), following Kinkazan A troop, was attacked one-sidedly by multiple members of the troop. The victim was identified as PI, and was estimated to be seven±one year old. The aggressive interaction was recorded by video camera until the end. Although at least 16 troop members approached PI more than once, only three males (one adult, two adolescents) of A troop attacked him. PI kept crouching throughout the attack, then escaped to the shore and dived into the sea. The interaction continued for more than one hour. PI was found dead a few hours after the end of interaction. The damage caused by the assailants was not the direct cause of PI's death; it was due to hypothermia caused by drifting in the sea. PI's life history was reconstructed from past records. PI was a normal adolescent male who migrated from an all-male group around B1 troop and started ranging around A troop. The aggressive interaction is believed to be a typical example of conflict between troop males and a nontroop male. The interaction period was very long compared with previous reports on such conflicts among Japanese macaques. PI kept crouching in open areas, exposing himself as a potential competitor for the resources of the troop, and did not show any submissive or reconciliatory behavior toward the troop males. This may be why the troop males did not stop the attack. Aggr. Behav. 35:334,341, 2009. © 2009 Wiley-Liss, Inc. [source] Possible Role of Pseudoephedrine and Other Over-the-Counter Cold Medications in the Deaths of Very Young ChildrenJOURNAL OF FORENSIC SCIENCES, Issue 2 2007William E. Wingert Ph.D. ABSTRACT: The Philadelphia Medical Examiners Office has reported a series of 15 deaths between February 1999 and June 2005 of infants and toddlers 16 months and younger in which drugs commonly found in over-the-counter (OTC) cold medications were present. A total of 10 different drugs were detected: pseudoephedrine, dextromethorphan, acetaminophen, brompheniramine, carbinoxamine, chlorpheniramine, ethanol, doxylamine and the anticonvulsants, phenobarbital, and phenytoin. The drugs were confirmed and quantified by gas chromatography (GC)-mass spectrometry, with the exception of ethanol, which was analyzed by headspace GC and of phenobarbital and phenytoin that were quantified by GC with a nitrogen phosphorus detector. The most predominant drug was pseudoephedrine, which was found in all of the cases (blood concentration, n=14, range=0.10,17.0 mg/L, mean=3.34 mg/L) and was the sole drug detected in three cases. Acetaminophen was detected in blood from each of the five cases with sufficient sample. Other drugs (with frequency of detection) were dextromethorphan (five cases), carbinoxamine (four cases), chlorpheniramine (two cases) and brompheniramine, doxylamine, and ethanol (one case each). In the majority of the cases, toxicity from drugs found in easily available OTC medications was listed either as the direct cause of death or as a contributory factor. The manner of death was determined to be natural in only two of the cases. This postmortem study supports previous evidence that the administration of OTC cold medications to infants may, under some circumstances, be an unsafe practice and in some cases may even be fatal. The treating physicians and the general public need to be made more aware of the dangers of using OTC cold medications to treat very young children so that these types of tragedies might be avoided. [source] Melatonin inhibits MPP+ -induced caspase-mediated death pathway and DNA fragmentation factor-45 cleavage in SK-N-SH cultured cellsJOURNAL OF PINEAL RESEARCH, Issue 2 2007Jirapa Chetsawang Abstract:, Neurodegenerative diseases such as Parkinson's disease are illnesses associated with high morbidity and mortality with few, or no effective, options available for their treatment. In addition, the direct cause of selective dopaminergic cell loss in Parkinson's disease has not been clearly understood. Taken together, several studies have demonstrated that melatonin has a neuroprotective effect both in vivo and in vitro. Accordingly, the effects of melatonin on 1-methyl, 4-phenyl, pyridinium ion (MPP+)-treated cultured human neuroblastoma SK-N-SH cell lines were investigated in the present study. The results showed that MPP+ significantly decreased cell viability. By contrast, an induction of phosphorylation of c-Jun, activation of caspase-3 enzyme activity, cleavage of DNA fragmentation factors 45 and DNA fragmentation were observed in MPP+ -treated cells. These changes were diminished by melatonin. These results demonstrate the cellular mechanisms of neuronal cell degeneration induced via c-Jun-N-terminal kinases and caspase-dependent signaling, and the potential role of melatonin on protection of neuronal cell death induced by this neurotoxin. [source] Huntington's disease,like 2 (HDL2) in North America and JapanANNALS OF NEUROLOGY, Issue 5 2004Russell L. Margolis MD Huntington's Disease,like 2 (HDL2) is a progressive, autosomal dominant, neurodegenerative disorder with marked clinical and pathological similarities to Huntington's disease (HD). The causal mutation is a CTG/CAG expansion mutation on chromosome 16q24.3, in a variably spliced exon of junctophilin-3. The frequency of HDL2 was determined in nine independent series of patients referred for HD testing or selected for the presence of an HD-like phenotype in North America or Japan. The repeat length, ancestry, and age of onset of all North American HDL2 cases were determined. The results show that HDL2 is very rare, with a frequency of 0 to 15% among patients in the nine case series with an HD-like presentation who do not have the HD mutation. HDL2 is predominantly, and perhaps exclusively, found in individuals of African ancestry. Repeat expansions ranged from 44 to 57 triplets, with length instability in maternal transmission detected in a repeat of 33 triplets. A younger age of onset is correlated with a longer repeat length (r2 = 0.29, p = 0.0098). The results further support the evidence that the repeat expansion at the chromosome 16q24.3 locus is the direct cause of HDL2 and provide preliminary guidelines for the genetic testing of patients with an HD-like phenotype. Ann Neurol 2004 An Erratum has been published for this article in Ann Neurol 56: 911, 2004. [source] Plant-Arthropod Associations from the Lower Miocene of the Most Basin in Northern Bohemia (Czech Republic): A Preliminary ReportACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2010Jakub PROKOP Abstract: Terrestrial plants and insects currently account for the majority of the Earth's biodiversity, and approximately half of insect species are herbivores. Thus, insects and plants share ancient associations that date back more than 400 Myr. However, investigations of their past interactions are at the preliminary stages in Western Europe. Herein, we present the first results of our study of various feeding damage based on a dataset of nearly 3500 examined plant specimens from the Lower Miocene of the Lagerstätte Bílina Mine in the Most Basin, Czech Republic. This site provides a unique view of the Neogene freshwater ecosystems. It has long been studied by scientists working in different branches of sedimentology, paleobotany, and paleozoology. The fossils are preserved in three characteristic horizons overlaying the coal seam (Clayey Superseam Horizon, Delta Sandy Horizon, and Lake Clayey Horizon), reflecting paleoenvironmental changes in a short time period of development. The trace fossils are classified as functional feeding groups or "guilds", without searching for a direct cause or a recent analog host relation. Approximately 23% of specimens of dicotyledonous plant leaves were found to be damaged and associated with some leaf "morphotypes". Deciduous plant-host taxa, and those with a chartaceous texture typical of riparian habitats, were frequently damaged, such as Populus, recorded with two species Populus zaddachii and Populus populina (57.9% and 31% herbivory levels, respectively), followed by Acer, Alnus, and Carya, averaging almost 30% of damaged leaves/leaflets. There has been evidence of 60 damage types (DT) representing all functional feeding groups recorded at the Bílina Mine, including 12 types of leaf mines and 16 gall-type DT. In total, Lower Miocene of the Lagerstätte Bílina Mine exhibits a high level of external foliage feeding types (23.7%), and a low level of more specialized DT, such as galls (4.3%) and leaf mines (<1%). A broader comparison based on DT of the main sedimentary environments shows significance supporting different biomes by frequency of damage levels and DT diversities. [source] Clinical outcomes of single-fraction stereotactic radiation therapy of lung tumors,CANCER, Issue 6 2006Ryusuke Hara M.D. Abstract BACKGROUND The objective of the current study was to investigate the effects and the morbidities of single-fraction stereotactic radiation therapy (SRT) for lung tumors. METHODS A Microtron device was modified to deliver stereotactic irradiation under respiratory gating. Between August 1998 and December 2004, 59 malignant lung tumors (11 primary tumors, 48 metastases) that measured < 40 mm in greatest dimension were treated by single-fraction SRT. Nine tumors received a minimal dose of < 30 grays (Gy), and 50 tumors received a minimal dose of , 30 Gy. The macroscopic target volume ranged from 1 cc to 19 cc (mean, 5 cc). RESULTS The 1-year and 2-year local progression-free rates (LPFRs) were 93% and 78%, respectively. The overall survival rate was 76.5% at 1 year and 41% at 2 years. Local regrowth of the irradiated tumor was a direct cause of death in two patients. Only the minimal radiation dose to the reference target volume tended to have an influence on the LPFR (P = 0.068). The 2-year LPFRs for patients who received irradiation doses of , 30 Gy and < 30 Gy were 83% and 52%, respectively. With regard to morbidities, Grade 3 respiratory symptoms (according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late radiation morbidity scoring scheme) were noted in one patient. CONCLUSIONS The results from the current study suggested that single-fraction SRT was tolerable and was capable of attaining excellent local control in patients who had malignant lung tumors that measured < 4 cm in greatest dimension. Cancer 2006. © 2006 American Cancer Society. [source] Is the endangered Grevy's zebra threatened by hybridization?ANIMAL CONSERVATION, Issue 6 2009J. E. Cordingley Abstract Hybridization between an abundant species and an endangered species is cause for concern. When such hybridization is observed, it is both urgent and necessary to assess the level of threat posed to the endangered species. We report the first evidence of natural hybridization between two equids: the endangered Grevy's zebra Equus grevyi and the abundant plains zebra Equus burchelli. Grevy's zebra now number <3000 individuals globally, and occur only in northern Kenya and Ethiopia. In recent years, Grevy's zebra have become increasingly concentrated in the south of their range due to habitat loss in the north. Both species are sympatric in the Laikipia ecosystem of northern Kenya, where we have observed purportedly hybrid individuals. Using mitochondrial and Y chromosome DNA, we confirmed the hybrid status of the morphologically identified hybrids and demonstrate conclusively that all first-generation hybrids are the offspring of plains zebra females and Grevy's zebra males. Behaviorally, hybrids integrate themselves into plains zebra society, rather than adopting the social organization of Grevy's zebra. Two hybrids have successfully raised foals to over 3 months in age, including one which has reached adulthood, indicating the fertility of female hybrids and viability of their offspring. We hypothesize that hybridization occurs due to (1) skewed sex ratios, in favor of males, within Grevy's zebra and (2) the numerical dominance of plains zebra in the region where hybridization is occurring. Stakeholders have discussed hybridization as a potential threat to Grevy's zebra survival. We argue, however, based on behavioral observations, that hybridization is unlikely to dilute the Grevy's zebra gene pool in the short term. As a conservation concern, hybridization is secondary to more direct causes of Grevy's zebra declines. [source] Rise in maternal mortality in the NetherlandsBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 4 2010JM Schutte Please cite this paper as: Schutte J, Steegers E, Schuitemaker N, Santema J, de Boer K, Pel M, Vermeulen G, Visser W, van Roosmalen J, the Netherlands Maternal Mortality Committee. Rise in maternal mortality in the Netherlands. BJOG 2009;117:399,406. Objective, To assess causes, trends and substandard care factors in maternal mortality in the Netherlands. Design, Confidential enquiry into the causes of maternal mortality. Setting, Nationwide in the Netherlands. Population, 2,557,208 live births. Methods, Data analysis of all maternal deaths in the period 1993,2005. Main outcome measures, Maternal mortality. Results, The overall maternal mortality ratio was 12.1 per 100 000 live births, which was a statistically significant rise compared with the maternal mortality ratio of 9.7 in the period 1983,1992 (OR 1.2, 95% CI 1.0,1.5). The most frequent direct causes were (pre-)eclampsia, thromboembolism, sudden death in pregnancy, sepsis, obstetric haemorrhage and amniotic fluid embolism. The number of indirect deaths also increased, mainly caused by an increase in cardiovascular disorders (OR 2.5, 95% CI 1.4,4.6). Women younger than 20 years and older than 45 years, those with high parity or from nonwestern immigrant populations were at higher risk. Most substandard care was found in women with pre-eclampsia (91%) and in immigrant populations (62%). Conclusions, Maternal mortality in the Netherlands has increased since 1983,1992. Pre-eclampsia remains the number one cause. Groups at higher risk for complications during pregnancy should be better identified early in pregnancy or before conception, in order to receive preconception advice and more frequent antenatal visits. There is an urgent need for the better education of women and professionals concerning the danger signs, and for the training of professionals in order to improve maternal health care. [source] God Does Not Play Dice: Causal Determinism and Preschoolers' Causal InferencesCHILD DEVELOPMENT, Issue 2 2006Laura E. Schulz Three studies investigated children's belief in causal determinism. If children are determinists, they should infer unobserved causes whenever observed causes appear to act stochastically. In Experiment 1, 4-year-olds saw a stochastic generative cause and inferred the existence of an unobserved inhibitory cause. Children traded off inferences about the presence of unobserved inhibitory causes and the absence of unobserved generative causes. In Experiment 2, 4-year-olds used the pattern of indeterminacy to decide whether unobserved variables were generative or inhibitory. Experiment 3 suggested that children (4 years old) resist believing that direct causes can act stochastically, although they accept that events can be stochastically associated. Children's deterministic assumptions seem to support inferences not obtainable from other cues. [source] | |||||||||||||||||||