Correlated responses on litter size traits and survival traits after two-stage selection for ovulation rate and litter size in rabbits

Farmer profit depends on the number of slaughter rabbits. The improvement of litter size (LS) at birth by two-stage selection for ovulation rate (OR) and LS could modify survival rate from birth to slaughter. This study was aiming to estimate direct and correlated response on LS traits and peri- and postnatal survival traits in the OR_LS rabbit line selected first only for OR (first period) and then for OR and LS using independent culling levels (second period). The studied traits were OR, LS measured as number of total born, number of kits born alive (NBA) and dead (NBD), and number of kits at weaning (NW) and young rabbits at slaughter (NS). Prenatal survival (LS/OR) and survival at birth (NBA/LS), at weaning (NW/NBA) and at slaughter (NS/NW) were also studied. Data were analysed using Bayesian inference methods. Heritability for LS traits were low, 0.07 for NBA, NW and NS. Survival traits had low values of heritability 0.07, 0.03 and 0.03 for NBA/LS, NW/NBA and NS/NW, respectively. After six generations of selection by OR (first period), a small increase in NBD and a slight decrease in NBA/LS were found. However, no correlated responses on NW/NBA and NS/NW were observed. After 11 generations of two-stage selection for OR and LS (second period), correlated responses on NBA, NW and NS were 0.12, 0.12 and 0.11 kits per generation, respectively, whereas no substantial modifications on NBA/LS, NW/NBA and NS/NW were found. In conclusion, two-stage selection improves the number of young rabbits at slaughter without modifying survival from birth to slaughter.     

Socioeconomic measures influence survival in osteosarcoma: an analysis of the National Cancer Data Base

BackgroundWhile previous studies have identified low socioeconomic status as a risk factor for metastatic disease in patients with high-grade osteosarcoma, the influence of socioeconomic status on overall survival remains unclear. The present study aims to investigate the relationship between survival and socioeconomic status in patients with high-grade conventional osteosarcoma.MethodsThe National Cancer Data Base (NCDB) was queried from 1998-2012 to identify all patients <40 years of age with a diagnosis of high-grade conventional osteosarcoma. A total of 3,503 patients were identified that met inclusion and exclusion criteria. Univariate relationships were investigated using Kaplan-Meier survival analysis and associated log-rank tests in order to determine patient, socioeconomic, tumor, and treatment variables associated with overall survival. Multivariate analysis was performed to determine independent predictors of survival.ResultsIn order of decreasing magnitude, metastatic disease (Hazard Ratio [HR] 3.28, 95% Confidence Interval [CI] 2.82-3.82), primary site in the pelvis or spine (HR 2.15, 95% CI 1.79-2.59), positive surgical margins (HR 1.82, 95% CI 1.46-2.27), tumor size >8 cm (HR 1.47, 95% CI 1.24-1.74), age ≥18 years (HR 1.30, 95% CI 1.14-1.48), lowest quartile of composite socioeconomic status (HR 1.23, 95% CI 1.02-1.51), and Medicaid insurance (HR 1.18, 95% CI 1.02-1.38) were predictors of decreased survival at 5 years.ConclusionTreating providers should be aware that some of their patients may have challenges unrelated to their diagnosis that make timely presentation, adherence to treatment, and continued close surveillance difficult. This investigation suggests that socioeconomic variables influence overall survival for osteosarcoma in the United States, although not as dramatically as established tumor- and treatment-related risk factors.     

Survival of body wall autographs, allografts, and xenografts in the earthworm Eisenia foetida.

It is acknowledged that autografts of Eisenia foetida body wall are accepted by their hosts. Allografts, however, have not been found to be accepted, although macroscopic observation of these might suggest they are, possibly owing to fusion of grafts and host epidermal cells. All xenografts eventually fail. Histological studies show that both allografts and xenografts were isolated from hosts, invaded, absorbed, and replaced with collagen. Statistical analyses of results from multiple transfers of xenografts show no evidence of hosts producing a heightened response of any nature to a second challenge of the same antigen.     

Fledgling survival increases with development time and adult survival across north and south temperate zones

Slow life histories are characterized by high adult survival and few offspring, which are thought to allow increased investment per offspring to increase juvenile survival. Consistent with this pattern, south temperate zone birds are commonly longer‐lived and have fewer young than north temperate zone species. However, comparative analyses of juvenile survival, including during the first few weeks of the post‐fledging period when most juvenile mortality occurs, are largely lacking. We combined our measurements of fledgling survival for eight passerines in South Africa with estimates from published studies of 57 north and south temperate zone songbird species to test three predictions: (1) fledgling survival increases with length of development time in the nest; (2) fledgling survival increases with adult survival and reduced brood size controlled for development time; and (3) south temperate zone species, with their higher adult survival and smaller brood sizes, exhibit higher fledgling survival than north temperate zone species controlled for development time. We found that fledgling survival was higher among south temperate zone species and generally increased with development time and adult survival within and between latitudinal regions. Clutch size did not explain additional variation, but was confounded with adult survival. Given the importance of age‐specific mortality to life history evolution, understanding the causes of these geographical patterns of mortality is important.     

Docosahexaenoic Acid Is Required for the Survival of Rat Retinal Photoreceptors In Vitro

Abstract: The effect of docosahexaenoic acid (DHA) on neuronal survival was studied in cultured cells isolated from newborn rat retina. In vivo, the content of DHA in the retina increased nearly fourfold from days 2 to 12 after birth, whereas in retinal cells in culture it remained constant. Unlike amacrine cells, the photoreceptor cells in control cultures underwent a selective degeneration, starting at day 7, that led to their massive death by day 11. The addition of DHA at day 7 led to its active incorporation by the cultures, increasing from 6 to 21% of total fatty acids in cell lipids, and completely prevented photo-receptor cell death. When other fatty acids were tested, both neuronal fatty acid composition and photoreceptor death were the same as in control cultures. These results indicate that DHA is specifically required for the survival of retinal photoreceptors.     

Integrated analysis of clinical significance and functional involvement of microRNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common lethal cancers worldwide. To explore the potential prognosis-associated microRNAs (miRNAs) for HCC patients, we performed integrated analyses on the miRNA expression profiles from The Cancer Genome Atlas project. Genome-wide overall survival (OS)- and progression-free survival (PFS)-associated miRNA screening were performed by multivariate Cox proportional hazards regression analyses. A five-miRNA expression signature (miR-148a, miR-3677-3p, miR-744*, miR-210, and miR-3613-5p) was identified as an indicator for HCC OS (p < .0001; hazard ratio [HR] = 2.631). In addition, a seven-miRNA expression signature (miR-127-5p, miR-146a, miR-152, miR-193a-3p, miR-331-5p, miR-500a*, and miR-550a*) was identified as a predictor for HCC PFS (p < .0001; HR = 2.608). This systematic analysis suggested that both the OS- and PFS-associated signatures have better performance in HCC survival prediction than the conventional clinicopathological parameters. Further functional enrichment analysis of the corresponding genes targeted by these signature miRNAs revealed their biological significance in the PI3K-Akt signaling pathway. In conclusion, our present study identified a five-miRNA OS-associated signature and a seven-miRNA PFS-associated signature as HCC prognostic biomarkers with potential clinical significance, which could enable the development of novel targeted therapeutic strategies for HCC treatment.     

Individual risk prediction: Comparing random forests with Cox proportional-hazards model by a simulation study

With big data becoming widely available in healthcare, machine learning algorithms such as random forest (RF) that ignores time-to-event information and random survival forest (RSF) that handles right-censored data are used for individual risk prediction alternatively to the Cox proportional hazards (Cox-PH) model. We aimed to systematically compare RF and RSF with Cox-PH. RSF with three split criteria [log-rank (RSF-LR), log-rank score (RSF-LRS), maximally selected rank statistics (RSF-MSR)]; RF, Cox-PH, and Cox-PH with splines (Cox-S) were evaluated through a simulation study based on real data. One hundred eighty scenarios were investigated assuming different associations between the predictors and the outcome (linear/linear and interactions/nonlinear/nonlinear and interactions), training sample sizes (500/1000/5000), censoring rates (50%/75%/93%), hazard functions (increasing/decreasing/constant), and number of predictors (seven, 15 including noise variables). Methods' performance was evaluated with time-dependent area under curve and integrated Brier score. In all scenarios, RF had the worst performance. In scenarios with a low number of events (⩽70), Cox-PH was at least noninferior to RSF, whereas under linearity assumption it outperformed RSF. Under the presence of interactions, RSF performed better than Cox-PH as the number of events increased whereas Cox-S reached at least similar performance with RSF under nonlinear effects. RSF-LRS performed slightly worse than RSF-LR and RSF-MSR when including noise variables and interaction effects. When applied to real data, models incorporating survival time performed better. Although RSF algorithms are a promising alternative to conventional Cox-PH as data complexity increases, they require a higher number of events for training. In time-to-event analysis, algorithms that consider survival time should be used.     

Social and maternal factors affecting duckling survival in eiders Somateria mollissima

1. With the aid of a novel survivorship model, an 8-year field study of social and maternal factors affecting duckling survival in eiders (Somateria mollissima) revealed that duckling survival probability varies in accordance with maternal brood-rearing strategy. This variability in survival provides compelling evidence of different annual fitness consequences between females that share brood-rearing and those that tend their broods alone. Consequently, as prebreeding survival is often a major source of individual variation in lifetime reproductive success, a female's annual, state-dependent (e.g. condition) choice of a brood-rearing strategy can be a critical fitness decision. 2. Variance in duckling survival among lone tender broods was best explained by a model with significant interannual variability in survival, and survivorship tending to increase with increasing clutch size at hatch. Clutch size was correlated positively with female condition. Hatch date and female body condition together affected duckling survival, but their contributions are confounded. We were unable to identify a relationship between female age or experience and duckling survival. 3. Variance in duckling survival among multifemale brood-rearing coalitions was best explained by a model that included the number of tenders, the number of ducklings and interannual variation in how their ratio affected survivorship. Hatch date did not significantly influence survival. 4. Expected duckling survival is higher in early life for lone tenders when compared with multifemale brood-rearing coalitions. However, as ducklings approach 2-3 weeks of age, two or three females was the optimal number of tenders to maximize daily duckling survival. The survivorship advantage of multifemale brood-rearing coalitions was most evident in years of average survival. 5. The observed frequency distribution of female group sizes corresponds with the distribution of offspring survival probabilities for these groups. Evidence for optimal group sizes in nature is rare, but the most likely candidates may be groups of unrelated animals where entry is controlled by the group members, such as for female eiders. 6. Our study demonstrates that differences in social factors can lead to different predictions of lifetime reproductive success in species with shared parental care of self-feeding young.     

Expected life years compared to the general population

For cohorts with long-term follow-up, the number of years lost due to a certain disease yields a measure with a simple and appealing interpretation. Recently, an overview of the methodology used for this goal has been published, and two measures have been proposed. In this work, we consider a third option that may be useful in settings in which the other two are inappropriate. In all three measures, the survival of the given dataset is compared to the expected survival in the general population which is calculated using external mortality tables. We thoroughly analyze the differences between the three measures, their assumptions, interpretation, and the corresponding estimators. The first measure is defined in a competing risk setting and assumes an excess hazard compared to the population, while the other two measures also allow estimation for groups that live better than the general population. In this case, the observed survival of the patients is compared to that in the population. The starting point of this comparison depends on whether the entry into the study is a hazard changing event (e.g., disease diagnosis or the age at which the inclusion criteria were met). Focusing on the newly defined life years difference measure, we study the estimation of the variance and consider the possible challenges (e.g., extrapolation) that occur in practice. We illustrate its use with a dataset of French Olympic athletes. Finally, an efficient R implementation has been developed for all three measures which make this work easily available to subsequent users.     

Peri-operative blood transfusion for resected colon cancer: Practice patterns and outcomes in a population-based study

Background & objectivesLiterature suggests that peri-operative blood transfusion among patients with resected colon cancer may be associated with inferior long-term survival. The study objective was to characterize this association in our population.MethodsThis is a retrospective cohort study using the population-based Ontario Cancer Registry (2002–2008). Pathology reports were obtained for a 25% random sample of all cases and constituted the study population. Log binomial regression was used to identify factors associated with transfusion. Cox proportional hazards model explored the association between transfusion and cancer specific survival (CSS) and overall survival (OS).ResultsThe study population included 7198 patients: 18% stage I, 36% stage II, 40% stage III, and 6% stage IV. Twenty-eight percent of patients were transfused. Factors independently associated with transfusion included advanced age (p < 0.001), female sex (p < 0.001), greater comorbidity (p < 0.001), more advanced disease (p < 0.001) and open surgical resection (p < 0.001). Transfusion was associated with inferior CSS (HR 1.51, 95% CI 1.38–1.65) and OS (HR 1.52, 95% CI 1.41–1.63), after adjusting for important confounders.ConclusionsPeri-operative transfusion rates among patients with colon cancer have decreased over time. Transfusion is associated with inferior long-term CSS and OS.     

The prognostic value of MGMT promoter methylation in glioblastoma: A meta‐analysis of clinical trials

The DNA repair protein O6‐Methylguanine‐DNA methyltransferase (MGMT) is suggested to be associated with resistance to alkylating agents such as Temozolomide which is being used in treatment of patients with glioblastoma (GBM). Therefore, we evaluated the associations between MGMT promoter methylation and prognosis of patients with glioblastoma (GBM). Data were extracted from publications in Embase, PubMed, and the Cochrane Library. Data on overall survival (OS), progression‐free survival (PFS), and MGMT methylation status were obtained and 4,097 subjects were enrolled. Data from 34 studies showed that MGMT methylated patients had better OS, compared to GBM unmethylated patients (pooled HRs, 0.494; 95%CI 0.412–0.591; p = 0.001). Meta‐analysis of 10 eligible studies reporting on PFS, demonstrated that MGMT promoter methylation was not significantly associated with better PFS (pooled HRs, 0.653; 95%CI 0.414–1.030; p = 0.067). GBM patients with MGMT methylation were associated with longer overall survival, although this effect was not detected for PFS. Moreover, we performed further analysis in patients underwent a comprehensive imaging evaluation. This data showed a significant association with better OS and PFS, although further studies are warranted to assess the value of emerging marker in prospective setting in patients with glioblastoma as a risk stratification biomarker in clinical management of the patients.     

Retroperitoneal soft-tissue sarcomas: Radiotherapy experience from a tertiary cancer center and review of current evidence

BackgroundSurgery remains to be the main therapeutic approach for retroperitoneal sarcomas (RPS) although evidence supports that complementary radiotherapy increases local-control and survival. We present a multidisciplinary management and experience of a tertiary cancer center in the treatment of RPS and analyze current evidence of radiotherapy efficacy.Patients and methodsWe retrospectively reviewed 19 patients with primary or relapsed RPS treated between November 2009 and October 2018. Multidisciplinary approach comprised complete resection in 15 patients (79%) achieving resection R0 in 11 patients (58%), R1 in 4 patients (21%) and R2 in 2 patients (10%). Seven patients (37%) underwent a preoperative radiation (PRORT), 10 patients (53%), post-operative radiation (PORT) and 2 patients (10%), received radiotherapy exclusively. Ten patients (53%) received adjuvant chemotherapy.ResultsWith a median follow-up of 24 months (2–114 months), actuarial rates of loco-regional relapse free survival (LRFS) at 1, 2 and 3 years were 77%, 77% and 67%, respectively. Actuarial rates of distant-metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) at 1, 2 and 3 years were 100%, 100% and 80% for DMFS; 94%, 77% and 67% for DFS and 100%, 91% and 91% for OS, respectively. Only surgical margins (negative vs. positive) showed significance for 3y-LRFS: 100% vs. 34.3%, p = 0.018. Treatment tolerance was acceptable with no acute or late toxicity higher than grade 2.ConclusionsComplementary radiotherapy appears to be useful and well tolerated for the multidisciplinary management of RPS. Presence of positive surgical margins seems to be the most relevant prognostic factor through the follow-up.     

Responses to land cover and grassland management vary across life‐history stages for a grassland specialist

Grassland birds have exhibited dramatic and widespread declines since the mid‐20th century. Greater prairie chickens (Tympanuchus cupido pinnatus) are considered an umbrella species for grassland conservation and are frequent targets of management, but their responses to land use and management can be quite variable. We used data collected during 2007–2009 and 2014–2015 to investigate effects of land use and grassland management practices on habitat selection and survival rates of greater prairie chickens in central Wisconsin, USA. We examined habitat, nest‐site, and brood‐rearing site selection by hens and modeled effects of land cover and management on survival rates of hens, nests, and broods. Prairie chickens consistently selected grassland over other cover types, but selection or avoidance of management practices varied among life‐history stages. Hen, nest, and brood survival rates were influenced by different land cover types and management practices. At the landscape scale, hens selected areas where brush and trees had been removed during the previous year, which increased hen survival. Hens selected nest sites in hay fields and brood‐rearing sites in burned areas, but prescribed fire had a negative influence on hen survival. Brood survival rates were positively associated with grazing and were highest when home ranges contained ≈15%–20% shrub/tree cover. The effects of landscape composition on nest survival were ambiguous. Collectively, our results highlight the importance of evaluating responses to management efforts across a range of life‐history stages and suggest that a variety of management practices are likely necessary to provide structurally heterogeneous, high‐quality habitat for greater prairie chickens. Brush and tree removal, grazing, hay cultivation, and prescribed fire may be especially beneficial for prairie chickens in central Wisconsin, but trade‐offs among life‐history stages and the timing of management practices must be considered carefully.     

Moisture Stress Effects on Survival of Infective Trichostrongylus colubriformis Larvae

Water was evaporated from infective Trichostrongylus colubriformis larvae suspended in tap, distilled, and triple-distilled water, and the nematodes were then exposed to 50% and 70% relative humidity (RH) at 20 and 30 C. Sample groups were rehydrated for 4 h daily in similar quality water, observed for motility and counted, then returned to the same RH and temp and re-desiccated. Desiccation and rehydration were repeated until all motility ceased. Longest survival was 30 days at 20 C and 70% RH. In all temp and RH combinations, control (nondesiccated) and desiccated larvae survived longer in distilled or triple-distilled water than in tap water.     

Relative survival analysis of gynecological cancers in an urban district of Shanghai during 2002–2013

ObjectiveAppraisal of cancer survival is essential for cancer control, but studies related to gynecological cancer are scarce. Using cancer registration data, we conducted an in-depth survival analysis of cervical, uterine corpus, and ovarian cancers in an urban district of Shanghai during 2002–2013.Materials and methodsThe follow-up data of gynecological cancer from the Changning District of Shanghai, China, were used to estimate the 1–5-year observed survival rate (OSR) and relative survival rate (RSR) by time periods and age groups during 2002–2013. Age-standardized relative survival rates estimated by the international cancer survival standards were calculated during 2002–2013 to describe the prognosis of cervical, uterine corpus, and ovarian cancers among women in the district.ResultsIn total, 1307 gynecological cancer cases were included in the survival analysis in the district during 2002–2013. Among gynecological cancers, the 5-year OSRs and RSRs of uterine corpus cancer were highest (5-year OSR 84.40%, 5-year RSR 87.67%), followed by those of cervical cancer (5-year OSR 73.58%, 5-year RSR 75.91%), and those of ovarian cancer (5-year OSR 53.89%, 5-year RSR 55.90%). After age adjustment, the 5-year relative survival rates of three gynecological cancers were 71.23%, 80.11%, and 43.27%, respectively.ConclusionThe 5-year relative survival rate did not show a systematic temporal trend in cervical cancer, uterine cancer, or ovarian cancer. The prognosis in elderly patients was not optimistic, and this needs a more advanced strategy for early diagnosis and treatment. The age structure of gynecological cancer patients in the district tended to be younger than the standardized age, which implies that more attention to the guidance and health education for the younger generation is needed.     

梵净山自然保护区珙桐天然种群生命表与生存分析

以种群生命表和生存分析理论为基础,采用空间代替时间法和分段匀滑技术,编制梵净山自然保护区珙桐天然种群特定时间生命表,绘制其死亡率曲线、消失率曲线、存活曲线和生存函数曲线,分析种群数量动态变化。结果表明:珙桐种群结构存在波动性,趋于DeeveyⅢ型,其幼年阶段的个体较丰富;珙桐种群死亡率和消失率曲线变化趋势基本一致,在这一发育过程中有两个死亡高峰,一个出现在幼苗向幼树的过渡期(Ⅰ龄级→Ⅱ龄级),另一个出现在从中龄向老龄过渡的阶段(Ⅷ龄级→Ⅸ龄级);种群生存分析表明,珙桐种群的生存率单调下降,累计死亡率单调上升,Ⅷ龄级后,种群生存率小于8%,累计死亡率大于92%,危险率超过生存率;4个生存函数曲线表明,梵净山珙桐有前期锐减、中期稳定和后期衰退的特点。幼苗和中龄级个体的不足是导致珙桐濒危的重要原因。     

毛囊蠕形螨的发育形态观察和存活适温范围研究

采用挤压涂片法或透明胶纸粘贴法获取毛囊蠕形螨,在数码显微镜Motic DM-B5软件系统下进行动态观察、拍摄和测量;然后对离体蠕形螨按批随机分组,观察不同温度下虫体的存活时间和活动力。结果系统地展示了毛囊蠕形螨发育过程各个时期的动态照片,发现毛囊蠕形螨的前若虫期有足4对,若虫期具有活动能力。离体实验表明,毛囊蠕形螨耐低温而不耐高温;存活适温范围在8～30℃之间,发育适温范围在20～30℃之间,发育最适温度为25～26℃;0℃以下或37℃以上温度对蠕形螨生存不利,54℃为致死温度,58℃为有效灭螨温度。这一研究结果为蠕形螨的体外培养和防治工作提供了可靠的理论依据。     

Disparate data streams together yield novel survival estimates of Alaska-breeding Whimbrels

Survival estimates are critical components of avian ecology. In well-intentioned efforts to maximize the utility of one's research, survival estimates often derive from data that were not originally collected for survival assessments, and such post hoc analyses may include unintentional biases. We estimated the survival of Whimbrels captured and marked at two breeding sites in Alaska using divergent data streams that in isolation were subject to methodological biases. Although both capture sites were chosen to study the migration ecology of Alaska-breeding Whimbrels, maximizing the conservation value of the data we collected was obviously desirable. We used multi-year telemetry information to infer survival from one site (Colville River) and mark–resight techniques to estimate survival from a second site (Kanuti River). At Colville River, we could not feasibly include a control group of birds to assess potential survival effects of externally mounted transmitters, and at Kanuti River we were unable to account accurately for potential emigration events because we used resightings alone. We integrated these datasets in a Bayesian hierarchical framework, an approach that permitted insights across sites that moderated methodological biases within sites. Using telemetry enabled us to detect permanent emigration events from breeding sites in two of 10 birds, results that informed estimates for birds without tracking devices. These datasets yielded point estimates of true survival of Whimbrels from Colville River equipped with solar-powered satellite transmitters that were higher (0.83) than true survival estimates of Whimbrels from Kanuti River marked with leg flags alone (0.74) or equipped with surgically implanted satellite transmitters (0.50), but the 95% credible intervals on these estimates overlapped across groups. For species such as Whimbrels that are difficult and costly to study, combining information from disparate data streams allowed us to derive novel demographic estimates, an approach with clear application to other similar studies.