145 research outputs found
Modelling the effect of environmental variables on the reproductive success of Griffon Vulture (Gyps fulvus) in Sardinia, Italy
Old World vultures are experiencing dramatic population declines and now are among
the species most threatened with extinction. Understanding the environmental variables
that can influence the reproductive indexes of vulture populations can facilitate both
habitat and species management. The aim of this study was to identify which environmental
variables primarily affect the breeding successes of the Griffon Vulture Gyps fulvus
in northern Sardinia by applying a Bayesian hierarchical model. A unique dataset of
reproductive records (197 nests monitored over 39 years for a total of 992 breeding
records) was used. Eight environmental and topographical variables describing the habitat
at the nesting sites were considered as potential predictors of breeding success. These
included mean annual temperature, mean annual precipitation, isothermality, elevation,
the normalized difference vegetation index, wind speed, and the aspect and slope of the
land surface. In addition, we also considered the effect of human disturbance and the
type of nest. According to our best model, the probability of successfully raising a chick
in Griffon Vultures was higher in nests exposed to a high wind speed, not covered by
natural shelters, where the vegetation was mostly represented by shrub and pastures,
with low human disturbance and in years with low rainfall. This model will be useful for
management of the breeding habitat and to identify the area most suitable for Griffon
Vulture reproduction. This information is crucial for programming conservation measures
aimed at enlarging the area of occupancy of the species.Postprin
Double Imprinted Nanoparticles for Sequential Membrane-to-Nuclear Drug Delivery
\ua9 2024 The Author(s). Advanced Science published by Wiley-VCH GmbH. Efficient and site-specific delivery of therapeutics drugs remains a critical challenge in cancer treatment. Traditional drug nanocarriers such as antibody-drug conjugates are not generally accessible due to their high cost and can lead to serious side effects including life-threatening allergic reactions. Here, these problems are overcome via the engineering of supramolecular agents that are manufactured with an innovative double imprinting approach. The developed molecularly imprinted nanoparticles (nanoMIPs) are targeted toward a linear epitope of estrogen receptor alfa (ERα) and loaded with the chemotherapeutic drug doxorubicin. These nanoMIPs are cost-effective and rival the affinity of commercial antibodies for ERα. Upon specific binding of the materials to ERα, which is overexpressed in most breast cancers (BCs), nuclear drug delivery is achieved via receptor-mediated endocytosis. Consequentially, significantly enhanced cytotoxicity is elicited in BC cell lines overexpressing ERα, paving the way for precision treatment of BC. Proof-of-concept for the clinical use of the nanoMIPs is provided by evaluating their drug efficacy in sophisticated three-dimensional (3D) cancer models, which capture the complexity of the tumor microenvironment in vivo without requiring animal models. Thus, these findings highlight the potential of nanoMIPs as a promising class of novel drug compounds for use in cancer treatment
Optogenetic Multiphysical Fields Coupling Model for Implantable Neuroprosthetic Probes
AuthorsOptogenetic-based neuroprosthetic therapies are increasingly being considered for human trials. However, the optoelectronic design of clinical-grade optogenetic-based neuroprosthetic probes still requires some thought. Design constraints include light penetration into the brain, stimulation efficacy, and probe/tissue heating. Optimisation can be achieved through experimental iteration. However, this is costly, time-consuming and ethically problematic. Hence it is highly desirable to have an alternative to excessive animal trials. Thus, a simulation tool for optimising probe design can be an important benefit for the community. The challenge is to understand the interplay between the optical, neural and thermal aspects in the interaction of probe and living neural tissue. In this work, we propose a model which combines these aspects to allow clinically orientated neuroprosthetic teams to design neuroprosthetic probes for optogenetic therapies. Our model provides analyses for optical, thermal and optogenetic electrophysiological processes based on the energy equivalence and exchange among different physical fields. To validate and calibrate the model, optogenetic implantable neuroprosthetic arrayed probes based on miniature LEDs were developed. Then, optical, thermal measurement and neural photocurrent recording experiments were implemented on the probes. We can then provide analysis on exemplar arrayed neural probes
Use of a neuroleptic in assisted reproduction of the critically endangered Mohor gazelle (Gazella dama mhorr)
Abstract Stress is a limiting factor in assisted reproduction in wild animals maintained in captivity and measures to reduce it should improve reproductive success. The effect of the long-acting neuroleptic (LAN) perphenazine enanthate was assessed on ovarian stimulation for the recovery of immature oocytes from Mohor gazelle (Gazella dama mhorr) and their subsequent in vitro maturation, fertilization and embryo culture. The viability of embryos after transfer was also examined. Perphenazine enanthate decreased activity levels and facilitated handling of treated animals when compared to controls. LAN-treated animals showed a more regular pattern of respiratory and heart rates and body temperature than controls; no major differences were found in hematological and biochemical parameters between groups. Perphenazine-treated females had lower plasma cortisol levels during the days of intense handling. No significant differences were found in the number of punctured follicles and recovered oocytes between groups. The percentage of mature oocytes per female was significantly higher in the LAN-group. Fertilization and cleavage rates were not significantly different between groups. Embryos developed in culture but none reached the blastocyst stage, and those transferred to the oviduct of synchronized recipients did not develop to term. In conclusion, treatment of females with perphenazine enanthate during ovarian stimulation did not have negative effects on maturation, fertilization and embryo development in vitro. Moreover, an increase in oocyte maturation rate per female was observed. Thus, the use of LANs could be useful to alleviate the effects of handling-stress during assisted reproductive procedures in wild ungulates.
Does the timing of pasture allocation affect rumen and plasma metabolites and ghrelin, insulin and cortisol profile in dairy ewes?
A study was undertaken to assess the impact of the timing of grazing on rumen and plasma metabolites and some metabolic hormones in lactating dairy sheep allocated to an Italian ryegrass (Lolium multiflorum Lam) pasture in spring for 4 h/d. Twenty-four mid lactation Sarda ewes stratified for milk yield, body weight, and body condition score, were divided into four homogeneous groups randomly allocated to the treatments (2 replicate groups per treatment). Treatments were morning (AM, from 08:00 to 12:00) and afternoon pasture allocation (PM, from 15:30 to 19:30). Samples of rumen liquor (day 39) and blood plasma (days 17 and 34 of the experimental period) were collected before and after the grazing sessions. Moreover, on days 11 and 35, grazing time was assessed by direct observation and herbage intake measured by the double weighing procedure. Grazing time was longer in PM than AM ewes (P < 0.001) but herbage intake was undifferentiated between groups. The intake of water-soluble carbohydrates at pasture was higher in PM than AM ewes (P < 0.05). The post-grazing propionic and butyric acid concentration, as measured on day 39, were higher in PM than AM ewes (P < 0.05). The basal level of glucose on day 34 and insulin (on both sampling days) were higher in PM than AM (P < 0.05). The opposite trend was detected for non-esterified fatty acids (P < 0.05, day 34) and urea (both days). Pasture allocation in the afternoon rather than in the morning decreased plasma concentration of ghrelin (P < 0.001) and cortisol (P < 0.001), with a smoothed trend on day 34 in the latter variable. To conclude, postponing the pasture allocation to afternoon increased the intake of WSC, favoring a glucogenic pattern of rumen fermentation and a rise of glucose and insulin levels in blood, although these effects were not consistent across the whole experimental period. Moreover, the afternoon grazing decreased the level of cortisol and ghrelin, suggesting a higher satiation-relaxing effect
Selection of young ewe lambs according to their antral follicular count: response to exogenous hormonal stimulation and fertility at first breeding season
Anti-Mullerian Hormone (AMH), Antral Follicular Count (AFC) and the response to exogenous hormonal stimulation have been used, in adults, as suitable markers to determine the ovarian reserve (1-4), to predict oocyte quality (5,6) and a wide variety of fertility indices (6-9). This investigation aims to evaluate if animals selected according to their High or Low AFC at an early prepubertal age show different responses, in the number of follicles and AMH plasma levels, to exogenous hormonal stimulation; to verify whether differences are maintained over time until puberty; and to observe possible variations on fertility at first breeding season
Double imprinted nanoparticles for sequential membrane‐to‐nuclear drug delivery
Efficient and site‐specific delivery of therapeutics drugs remains a critical challenge in cancer treatment. Traditional drug nanocarriers such as antibody‐drug conjugates are not generally accessible due to their high cost and can lead to serious side effects including life‐threatening allergic reactions. Here, these problems are overcome via the engineering of supramolecular agents that are manufactured with an innovative double imprinting approach. The developed molecularly imprinted nanoparticles (nanoMIPs) are targeted toward a linear epitope of estrogen receptor alfa (ERα) and loaded with the chemotherapeutic drug doxorubicin. These nanoMIPs are cost‐effective and rival the affinity of commercial antibodies for ERα. Upon specific binding of the materials to ERα, which is overexpressed in most breast cancers (BCs), nuclear drug delivery is achieved via receptor‐mediated endocytosis. Consequentially, significantly enhanced cytotoxicity is elicited in BC cell lines overexpressing ERα, paving the way for precision treatment of BC. Proof‐of‐concept for the clinical use of the nanoMIPs is provided by evaluating their drug efficacy in sophisticated three‐dimensional (3D) cancer models, which capture the complexity of the tumor microenvironment in vivo without requiring animal models. Thus, these findings highlight the potential of nanoMIPs as a promising class of novel drug compounds for use in cancer treatment
Distinctive features of orbital adipose tissue (OAT) in Graves’ Orbitopathy
Depot specific expansion of orbital-adipose-tissue (OAT) in Graves’ Orbitopathy (GO) is associated with lipid metabolism signaling defects. We hypothesize that the unique adipocyte biology of OAT facilitates its expansion in GO. A comprehensive comparison of OAT and white-adipose-tissue (WAT) was performed by light/electron-microscopy, lipidomic and transcriptional analysis using ex vivo WAT, healthy OAT (OAT-H) and OAT from GO (OAT-GO). OAT-H/OAT-GO have a single lipid-vacuole and low mitochondrial number. Lower lipolytic activity and smaller adipocytes of OAT-H/OAT-GO, accompanied by similar essential linoleic fatty acid (FA) and (low) FA synthesis to WAT, revealed a hyperplastic OAT expansion through external FA-uptake via abundant SLC27A6 (FA-transporter) expression. Mitochondrial dysfunction of OAT in GO was apparent, as evidenced by the increased mRNA expression of uncoupling protein 1 (UCP1) and mitofusin-2 (MFN2) in OAT-GO compared to OAT-H. Transcriptional profiles of OAT-H revealed high expression of Iroquois homeobox-family (IRX-3&5), and low expression in HOX-family/TBX5 (essential for WAT/BAT (brown-adipose-tissue)/BRITE (BRown-in-whITE) development). We demonstrated unique features of OAT not presented in either WAT or BAT/BRITE. This study reveals that the pathologically enhanced FA-uptake driven hyperplastic expansion of OAT in GO is associated with a depot specific mechanism (the SLC27A6 FA-transporter) and mitochondrial dysfunction. We uncovered that OAT functions as a distinctive fat depot, providing novel insights into adipocyte biology and the pathological development of OAT expansion in GO
Effect of storage temperature during transport of ovaries on in vitro embryo production in Iberian red deer (Cervus elaphus hispanicus)
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