Average Survival (average + survival)

Distribution by Scientific Domains


Selected Abstracts


Effect of feeding scheme and prey density on survival and development of Chinese mitten crab Eriocheir sinensis zoea larvae

AQUACULTURE RESEARCH, Issue 6 2008
Li-ying Sui
Abstract The effect of feeding scheme and prey density on survival and development of Eriocheir sinensis zoea larvae was studied in three experiments. Different combinations and densities of rotifers (Brachionus rotundiformis) and newly hatched Artemia nauplii were fed to zoea larvae. Average survival at each stage, larval development (larval stage index, LSI), duration of zoeal stage and individual megalopa dry weight were compared among treatments. This study revealed that, under the experimental conditions, rotifers should be replaced with Artemia between the zoea 3 (Z3) and the zoea 4 (Z4) stage. The optimal rotifer feeding densities for zoea 1 (Z1) and zoea 2 (Z2) were 15 and 20 mL,1 respectively, while the optimal Artemia feeding density for Z3, Z4 and zoea 5 (Z5) was 3, 5 and 8 mL,1 respectively. Further trials in production scale are recommended. [source]


Rainfall in arid zones: possible effects of climate change on the population ecology of blue cranes

FUNCTIONAL ECOLOGY, Issue 5 2009
Res Altwegg
Summary 1.,Understanding the demographic mechanisms through which climate affects population dynamics is critical for predicting climate change impacts on biodiversity. In arid habitats, rainfall is the most important forcing climatic factor. Rainfall in arid zones is typically variable and unpredictable, and we therefore hypothesise that its seasonality and variability may be as important for the population ecology of arid zone animals as its total amount. 2.,Here we examine the effect of these aspects of rainfall on reproduction and age specific survival of blue cranes (Anthropoides paradiseus Lichtenstein) in the semi-arid eastern Nama Karoo, South Africa. We then use our results to predict the effect of changes in rainfall at the population level. 3.,Using combined capture-mark-resighting and dead-recovery models, we estimated average survival of cranes to be 0·53 in their first year, 0·73 in their second and third year, and 0·96 for older birds. 4.,We distinguished between three seasons, based on the blue cranes' breeding phenology: early breeding season, late breeding season and nonbreeding season. Cranes survived better with increasing rainfall during the late but not early breeding season. Based on road counts and success of monitored nests, reproduction was positively associated with rainfall during the early but not late breeding season. 5.,A matrix population model predicted that population growth rate would increase with increasing rainfall. A stochastic analysis showed that variation in early breeding season rainfall increased population growth slightly due to the nonlinear relationship between rainfall and reproduction. This effect was opposed by the effect of variation in late breeding season rainfall on survival and overall, variation in rainfall had a negligible effect on population growth. 6.,Our results allow predictions to be made for a range of climate-change scenarios. For example, a shift in seasonality with drier springs but wetter summers would likely decrease reproduction but increase survival, with little overall effect on population growth. [source]


Cutaneous metastasis: a clinical, pathological, and immunohistochemical appraisal

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2004
Sadia Saeed
Background:, Cutaneous tumor metastasis may be the first manifestation of cancer, but more often is a harbinger of advanced disease that portends an ominous prognosis. All skin accessions over the past 10 years from a large Veterans Administration (VA) hospital were reviewed. Methods:, Archived histories, glass slides, and the immunohistochemical battery (IHC), were assessed to determine diagnostic accuracy. Results:, Of the 100,453 cases reviewed, there were a total of 77 cases (75 males and 2 females) of cutaneous metastasis from the lungs (28.6%), metastatic melanoma (18.2%), gastrointestinal tract (14.2%), genitourinary tract (10.4%), head and neck (9.1%), hematologic (5.2%), breast (5.2%), and miscellaneous (<2%). Metastasis represented the first indication of an internal malignancy in 7.8% of cases. The cutaneous sites of involvement included the head and neck (28%), the trunk (40%), the extremities (18%), and multiple sites (14%). The age range was 38,83 years, with a mean of 62 years. The average time interval between diagnosis of internal malignancy and cutaneous presentation was 33 months (range: <1 month,22 years), and the average survival following diagnosis was 7.5 months (range: <1 month,8 years). In a cohort of subjects, a truncated immunohistochemical battery consisting of CK-7, CK-20, and S-100 was consistent with the expected staining pattern of the primary source of cutaneous metastasis in 83.33% of the patients. Conclusions:, Excluding the potential for age and gender bias in this study conducted in a VA setting, cutaneous metastases represent an uncommon, deadly, and late-developing occurrence in many patients. Compared with previous studies, lung carcinoma remains the most common of the cutaneous metastases, with a relative rise in the incidence of metastatic melanoma. The immunohistochemical battery of CK-7, CK-20, and S-100 is a helpful adjunct in narrowing the differential diagnosis of the primary site of a large proportion of cutaneous metastases, particularly tumors with an epithelioid appearance such as carcinomas and melanomas. [source]


Natural history of hepatocellular carcinoma including fibrolamellar and hepato-cholangiocarcinoma variants

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 4 2002
Kunio Okuda
Abstract The natural history of hepatocellular carcinoma (HCC) varies greatly with the global region, because the carcinogenic factors are not the same among countries. Besides the clinicopathological factors such as tumor characteristics, sex, and age, background liver disease is a major determinant of prognosis. Hepatocellular carcinoma, mainly associated with chemical carcinogens such as aflatoxin, does not have severe background cirrhosis, and grows quickly, whereas HCC developing in association with a virus in a cirrhotic liver generally grows more slowly, and the severity of cirrhosis is the major prognostic factor. The median survival of untreated sub-Saharan African patients is less than 1 month from diagnosis, contrasted by an average survival of 4 months in virus-induced HCC associated with cirrhosis. Tumor characteristics, such as size, number, and growth speed, which vary considerably from case to case, affect the prognosis. Vascular (portal) invasion portends a poor prognosis, and ,-fetoprotein levels also correlate with prognosis. Several distinct clinical types of HCC occur, namely diffuse-type HCC caused by rapid portal spread of cancer cells, febrile-type caused by poorly differentiated sarcomatoid cancer cells, and cholestatic HCC caused by intraductal invasion; all have a short survival. There are several histological variant forms: combined hepato-cholangiocarcinoma behaves like HCC, with a poorer prognosis because of more frequent lymph node metastases; fibromellar carcinoma, which is relatively common in young Caucasian adults, has a good prognosis if diagnosed early, permitting resection; and cholangiolocellular carcinoma, which derives from the canalicular epithelium, is indistinguishable from HCC, with a similar prognosis. © 2002 Blackwell Publishing Asia Pty Ltd [source]


Patients' preference for radiotherapy fractionation schedule in the palliation of symptomatic unresectable lung cancer,

JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 5 2008
JI Tang
Summary The palliative radiotherapeutic management of unresectable non-small-cell lung cancer is controversial, with various fractionation (Fx) schedules available. We aimed to determine patient's choice of Fx schedule after involvement in a decision-making process using a decision board. A decision board outlining the various advantages and disadvantages apparent in the Medical Research Council study of Fx schedules (17 Gy in two fractions vs 39 Gy in 13 fractions) was discussed with patients who met Medical Research Council eligibility criteria. Patients were then asked to indicate their preferred Fx schedules, reasons and their level of satisfaction with being involved in the decision-making process. Radiation oncologists (RO) could prescribe radiotherapy schedules irrespective of patients' preferences. Of 92 patients enrolled, 55% chose the longer schedule. English-speaking patients were significantly more likely to choose the longer schedule (P = 0.02, 95% confidence interval: 1.2,7.6). Longer Fx was chosen because of longer survival (90%) and better local control (12%). Shorter Fx was chosen for shorter overall treatment duration (80%), cost (61%) and better symptom control (20%). In all, 56% of patients choosing the shorter schedule had their treatment altered by the treating RO, whereas only 4% of patients choosing longer Fx had their treatment altered (P < 0.001). Despite this, all (100%) patients were satisfied with being involved in the decision-making process. The decision board was useful in aiding decision-making, with both Fx schedules being acceptable to patients. Interestingly, despite the longer average survival associated with longer Fx, nearly half of the patients believed that this was not as important as a shorter duration of treatment and lower cost. Despite patients' preferences, there were significant alterations of preferred schedules because of RO's own biases. [source]


The intratumoral distribution of nuclear ,-catenin is a prognostic marker in colon cancer

CANCER, Issue 10 2009
David Horst MD
Abstract BACKGROUND: Most colon cancers harbor mutations of APC or ,-catenin, both of which may lead to nuclear ,-catenin accumulation in the tumor cells and constitutively activated expression of its target genes. In many colon cancers, however, nuclear ,-catenin accumulation is heterogeneous throughout the tumor and often confined to the tumor margin. Herein, the authors investigated whether the intratumoral distribution of nuclear ,-catenin can serve as a prognostic marker for survival and tumor progression of stage IIA colon cancer patients. METHODS: In total, 142 patients with primarily resected, moderately differentiated stage IIA colon cancer were included in this study. The patterning of nuclear ,-catenin expression was evaluated on immunohistochemically stained whole tissue sections of the tumors and was correlated with cancer-specific survival and disease-free survival using univariate and multivariate statistical analyses. RESULTS: Four distinct patterns of nuclear ,-catenin expression were identified, and 2 main categories comprising tumors with or without intratumoral regulation of nuclear ,-catenin were distinguished. Moreover, the results demonstrated that the patterning, and especially the regulation or absence of regulation of nuclear ,-catenin expression, was a strong predictive marker of patient survival and tumor progression. CONCLUSIONS: The current results indicated that the distribution of nuclear ,-catenin expression can be used as a good prognostic marker in patients with stage IIA colon cancer. Thus, the evaluation of nuclear ,-catenin may help to identify patients who will have a shorter than average survival and patients with a greater risk of disease progression who may be considered for adjuvant therapeutic modalities and intensified clinical aftercare in the future. Cancer 2009. © 2009 American Cancer Society. [source]