scholarly journals Non-invasive assessment of oestrous cycles and evaluation of reproductive seasonality in the female wild black rhinoceros (Diceros bicornis minor)

Reproduction ◽  
2002 ◽  
pp. 877-889 ◽  
Author(s):  
JN Garnier ◽  
WV Holt ◽  
PF Watson
Keyword(s):  
Rainy Season ◽  
Total Duration ◽  
Reproductive Behaviour ◽  
Early Embryo ◽  
Early Summer ◽  
Normal Cycle ◽  
Black Rhinoceros ◽  
Non Invasive ◽  
Progesterone Metabolite ◽  
Suitable Environment

Female wild black rhinoceroses in Zimbabwe were monitored non-invasively using faecal progesterone metabolite analysis and observation of reproductive behaviour. A postpartum period of reproductive inactivity of at least 4 months, followed by a period of 4-7 months of oestrous cyclicity, was detected in six multiparous females. Three-quarters of the oestrous cycles (n = 21) had a total duration (mean +/- SEM) of 26.8 +/- 1 days. Other types of cycle were characterized either by an extended luteal phase, lasting on average twice as long as the normal cycle, or by an extended follicular phase. These extended cycles may have resulted from early embryo loss and heat stress. Female rhinoceroses did not conceive before 8 months after giving birth and some females (n = 2) most likely aborted after 3.0-3.5 months of gestation. The detected period of cyclic oestrus occurred between May and March in females (n = 9), and there was a 3 month extended interoestrous interval in nulliparous females during the period of decreasing daylengths that can be presumed to be the period of poorest fertility for the black rhinoceros under tropical latitudes. In contrast, the period of optimum fertility in the Southern hemisphere coincided with the late spring and early summer, and corresponded to the early rainy season. As a result, a higher incidence of births was detected in the late rainy season, providing the lactating female with the most suitable environment in terms of nutritional requirements.

scholarly journals Aboveground Net Primary Production at Acacia mangium Plantation in Northern Vietnam

2019 ◽  
pp. 1-7
Author(s):  
Nguyen Toan Thang ◽  
Vu Tien Lam ◽  
Dang Van Thuyet ◽  
Phung Dinh Trung ◽  
Pham Dinh Sam ◽  
...  
Keyword(s):  
Primary Production ◽  
Aboveground Biomass ◽  
Rainy Season ◽  
Net Primary Production ◽  
Total Duration ◽  
Acacia Mangium ◽  
Soil Nutrient ◽  
Early Summer ◽  
Biomass Increment ◽  
Soil Nutrient Cycling

Net primary production (NPP) is an important index for understanding carbon cycling in forest ecosystems. In this study, aboveground NPP at Acacia mangium plantation was estimated basing on allometry for aboveground biomass increment (ΔM) and litter trap technique for litterfall (Lf). The experiment was conducted in two plots of 300 m2 each (15 × 20 m), established at a 21-month old plantation. Data were collected five times of 3-month intervals in a total duration of 357 days. The results indicated that Lf and ΔM were seasonal-dependent. Litterfall was highest (4.06 g m-1 day-1) during Sep-Jan (late rainy season, early winter) and lowest (1.10 g m-1 day-1) during Mar-Jun (early rainy season, early summer). While, ΔM was highest (13.51 g m-1 day-1) during Jun-Sep (rainy season, summer) and lowest (3.10 g m-1 day-1) during Jan-Mar (dry season, winter). Total Lf in a duration of 357 days was 9.69 tons ha-1 and ΔM was 27.71 tons ha-1, leading to total aboveground NPP of the present study plantation of 37.40 tons ha-1. It is concluded that aboveground NPP of acacia plantation was much higher than other forests of different types and ages around the world. Such difference indicates the importance of acacia plantation in soil nutrient cycling through litterfall decomposition and carbon sequestration through aboveground biomass increment.

scholarly journals Identifying unknown Indian wolves by their distinctive howls: its potential as a non-invasive survey method

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sougata Sadhukhan ◽  
Holly Root-Gutteridge ◽  
Bilal Habib
Keyword(s):  
Reproductive Behaviour ◽  
Identification Accuracy ◽  
Individual Identification ◽  
Survey Method ◽  
Reliable Estimate ◽  
Mark Recapture ◽  
Test Dataset ◽  
Individual Level ◽  
Non Invasive ◽  
Supervised Classification Methods

AbstractPrevious studies have posited the use of acoustics-based surveys to monitor population size and estimate their density. However, decreasing the bias in population estimations, such as by using Capture–Mark–Recapture, requires the identification of individuals using supervised classification methods, especially for sparsely populated species like the wolf which may otherwise be counted repeatedly. The cryptic behaviour of Indian wolf (Canis lupus pallipes) poses serious challenges to survey efforts, and thus, there is no reliable estimate of their population despite a prominent role in the ecosystem. Like other wolves, Indian wolves produce howls that can be detected over distances of more than 6 km, making them ideal candidates for acoustic surveys. Here, we explore the use of a supervised classifier to identify unknown individuals. We trained a supervised Agglomerative Nesting hierarchical clustering (AGNES) model using 49 howls from five Indian wolves and achieved 98% individual identification accuracy. We tested our model’s predictive power using 20 novel howls from a further four individuals (test dataset) and resulted in 75% accuracy in classifying howls to individuals. The model can reduce bias in population estimations using Capture-Mark-Recapture and track individual wolves non-invasively by their howls. This has potential for studies of wolves’ territory use, pack composition, and reproductive behaviour. Our method can potentially be adapted for other species with individually distinctive vocalisations, representing an advanced tool for individual-level monitoring.

Is there still a rationale for non-invasive PGT-A by analysis of cell-free DNA released by human embryos into culture medium?

2021 ◽  
Vol 36 (5) ◽  
pp. 1186-1190
Author(s):  
Raoul Orvieto ◽  
Adva Aizer ◽  
Norbert Gleicher
Keyword(s):  
Culture Media ◽  
Chromosomal Rearrangements ◽  
Primary Source ◽  
Normal Pregnancy ◽  
Early Embryo ◽  
Human Embryos ◽  
Cell Debris ◽  
Cell Free Dna ◽  
Non Invasive ◽  
Free Dna

Abstract Human embryos utilise an array of processes to eliminate the very high prevalence of aneuploid cells in early embryo stages. Human embryo self-correction was recently demonstrated by their ability to eliminate/expel abnormal blastomeres as cell debris/fragments. A whole genome amplification study has demonstrated that 63.6% of blastocysts expelled cell debris with abnormal chromosomal rearrangements. Moreover, 55.5% of euploid blastocysts expel aneuploid debris, strongly suggesting that the primary source of cell free DNA in culture media is expelled aneuploid blastomeres and/or their fragments. Such a substantial ability to self-correct downstream from the blastocyststage, therefore, renders any chromosomal diagnosis at the blastocyststage potentially useless, and this, unfortunately, also must particularly include non-invasive PGT-A based on cell-free DNA in spent medium. High rates of false-positive diagnoses of human embryos often lead to non-use and/or disposal of embryos with entirely normal pregnancy potential. Before adopting yet another round of unvalidated PGT-A as a routine adjunct to IVF, we here present facts that deserve to be considered.

Contrasting frontal and warm-sector heavy rainfalls over South China during the early-summer rainy season

2020 ◽  
Vol 235 ◽  
pp. 104693 ◽  
Author(s):  
Naigeng Wu ◽  
Xi Ding ◽  
Zhiping Wen ◽  
Guixing Chen ◽  
Zhiyong Meng ◽  
...  
Keyword(s):  
South China ◽  
Rainy Season ◽  
Early Summer ◽  
Warm Sector ◽  
Heavy Rainfalls

scholarly journals The Biological Function of Extracellular Vesicles during Fertilization, Early Embryo—Maternal Crosstalk and Their Involvement in Reproduction: Review and Overview

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1510
Author(s):  
Emanuele Capra ◽  
Anna Lange-Consiglio
Keyword(s):  
Extracellular Vesicles ◽  
Spatial Interaction ◽  
Cell Communication ◽  
Early Embryo ◽  
Molecular Profile ◽  
Cell Of Origin ◽  
Non Invasive ◽  
Temporal And Spatial ◽  
Mediate Cell

Secretory extracellular vesicles (EVs) are membrane-enclosed microparticles that mediate cell to cell communication in proximity to, or distant from, the cell of origin. Cells release a heterogeneous spectrum of EVs depending on their physiologic and metabolic state. Extracellular vesicles are generally classified as either exosomes or microvesicles depending on their size and biogenesis. Extracellular vesicles mediate temporal and spatial interaction during many events in sexual reproduction and supporting embryo-maternal dialogue. Although many omic technologies provide detailed understanding of the molecular cargo of EVs, the difficulty in obtaining populations of homogeneous EVs makes difficult to interpret the molecular profile of the molecules derived from a miscellaneous EV population. Notwithstanding, molecular characterization of EVs isolated in physiological and pathological conditions may increase our understanding of reproductive and obstetric diseases and assist the search for potential non-invasive biomarkers. Moreover, a more precise vision of the cocktail of biomolecules inside the EVs mediating communication between the embryo and mother could provide new insights to optimize the therapeutic action and safety of EV use.

Non-invasive ventilation versus invasive weaning in critically ill adults: a systematic review and meta-analysis

Thorax ◽  
2021 ◽  
pp. thoraxjnl-2021-216993
Author(s):  
Karen E A Burns ◽  
James Stevenson ◽  
Matthew Laird ◽  
Neill K J Adhikari ◽  
Yuchong Li ◽  
...  
Keyword(s):  
Critically Ill ◽  
Total Duration ◽  
Cochrane Central Register ◽  
Invasive Ventilation ◽  
High Quality ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Critically Ill Adults ◽  
Ill Adults ◽  
Duration Of Ventilation

BackgroundExtubation to non-invasive ventilation (NIV) has been investigated as a strategy to wean critically ill adults from invasive ventilation and reduce ventilator-related complications.MethodsWe searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, proceedings of four conferences and bibliographies (to June 2020) for randomised and quasi-randomised trials that compared extubation with immediate application of NIV to continued invasive weaning in intubated adults and reported mortality (primary outcome) or other outcomes. Two reviewers independently screened citations, assessed trial quality and abstracted data.ResultsWe identified 28 trials, of moderate-to-good quality, involving 2066 patients, 44.6% with chronic obstructive pulmonary disease (COPD). Non-invasive weaning significantly reduced mortality (risk ratio (RR) 0.57, 95% CI 0.44 to 0.74; high quality), weaning failures (RR 0.59, 95% CI 0.43 to 0.81; high quality), pneumonia (RR 0.30, 95% CI 0.22 to 0.41; high quality), intensive care unit (ICU) (mean difference (MD) −4.62 days, 95% CI −5.91 to −3.34) and hospital stay (MD −6.29 days, 95% CI −8.90 to −3.68). Non-invasive weaning also significantly reduced the total duration of ventilation, duration of invasive ventilation and duration of ventilation related to weaning (MD −0.57, 95% CI −1.08 to −0.07) and tracheostomy rate. Mortality, pneumonia, reintubation and ICU stay were significantly lower in trials enrolling COPD (vs mixed) populations.ConclusionNon-invasive weaning significantly reduced mortality, pneumonia and the duration of ventilation related to weaning, particularly in patients with COPD. Beneficial effects are less clear (or more careful patient selection is required) in non-COPD patients.PROSPERO registration numberCRD42020201402.

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