Reproductive Capability Research Articles

C-Type Lectins Link Immunological and Reproductive Processes in Aedes aegypti.

SummaryPhysiological trade-offs between mosquito immune response and reproductive capability can arise due to insufficient resource availability. C-type lectin family members may be involved in these processes. We established a GCTL-3−/− mutant Aedes aegypti using CRISPR/Cas9 to investigate the role of GCTL-3 in balancing the costs associated with immune responses to arboviral infection and reproduction. GCTL-3−/− mutants showed significantly reduced DENV-2 infection rate and gut commensal microbiota populations, as well as upregulated JAK/STAT, IMD, Toll, and AMPs immunological pathways. Mutants also had significantly shorter lifespans than controls and laid fewer eggs due to defective germ line development. dsRNA knock-down of Attacin and Gambicin, two targets of the AMPs pathway, partially rescued this reduction in reproductive capabilities. Upregulation of immune response following GCTL-3 knock-out therefore comes at a cost to reproductive fitness. Knock-out of other lectins may further improve our knowledge of the molecular and genetic mechanisms underlying reproduction-immunity trade-offs in mosquitoes.

"There Is Nothing to Do About It": Nonbinary Individuals' Experience of Gender Dysphoria.

Purpose: Clinical definitions of gender dysphoria have primarily centered on a binary conceptualization of gender. This study aimed to understand nonbinary transindividuals' experiences of gender dysphoria. Methods: Data were collected online from a nonclinical sample comprised of 205 nonbinary and agender participants. Analysis focused on answers to a single open-ended question prompting participants to describe their gender dysphoria as it relates to their body and/or appearance. Results: First, content analysis was used to document 11 contextual elements in which participants described their dysphoria with regard to three overarching categories, including no gender dysphoria (no issues with body, no dysphoria), aspects of gender/sex (naming gender identity, naming assigned sex, gender role, or expression), and aspects of body (body shape, genitals, chest, secondary sex characteristics, hormones, reproductive capability). Second, thematic analysis revealed six central themes describing the unique way gender dysphoria is experienced by nonbinary individuals: (1) Androgyny or Fluidity, (2) Feminine and Masculine Traits, (3) Dysphoria vs. Expression or Appearance, (4) Varying or Shifting Dysphoria, (5) No Solution, and (6) Trade-off/Loss. Conclusion: Results of this study suggest that nonbinary transindividuals experience gender dysphoria in unique ways. These findings highlight the need to develop clinical assessments of gender dysphoria that reflect nonbinary experience, and to outline explicit medical protocols for interventions tailored to achieve a desired outcome of physical androgyny.

A novel testicular degenerative condition in a wild population of the common carp Cyprinus carpio (L).

Gonad abnormalities can restrict or completely block reproductive capability of individuals and in some case that of their populations. Here, we describe a novel testicular degenerative condition of non-germ cell origin with a high prevalence (up to 22.1% of the population) in a wild population of carp. Based on gross morphology, and microscopic and cellular examinations, the condition shows progressive severity which could be categorized into low, mild, severe and complete. In early stages of the condition, an abnormally increased proliferation (11-fold) of the Sertoli cell occurred, followed by degenerative cell death of all testicular cells, resulting in fluid-filled vesicles in the later stages. This initial uncontrolled proliferation of Sertoli cells suggests that the condition could be triggered by malignant pathways; however, the observed subsequent apoptosis of all testicular cells en masse, rendering the animals "sterile," appears unique. Observations, to date, indicate that this condition is specific to male carp and not present in other species of fish sharing the habitat. High prevalence of the condition allowed comparative evaluation between affected individuals, an aspect likely to facilitate future studies, including elucidation of the cause, robust testing of therapies and practical applications such as management of feral carp populations.

CRISPR/Cas9 gene drive technology to control transmission of vector-borne parasitic infections.

Gene drive is the process of copying of an endonuclease-containing cassette that leads to increased frequency of inheritance of the desired traits in a targeted population. CRISPR/Cas9 technology is advancing genetic manipulation of insects in the field of gene drive experiments. The CRISPR/Cas9 drive could be engineered for genetic manipulation of parasites and/or vectors for disease control. A number of promising CRISPR/Cas9-based gene drive strategies that interfere with parasite development or impairs the reproductive capability of the insect vector have been proposed in the laboratory for blocking transmission of malaria and leishmaniasis. Still several technical and ethical challenges remain to be addressed, and none appear insuperable in this field.

Impairment of reproductive capabilities in three subsequent generations of asymmetric hybrids between Eisenia andrei and E. fetida from French, Hungarian and Polish laboratory colonies.

Eisenia andrei (Ea) and E. fetida (Ef) lumbricid earthworms are simultaneous hermaphrodites potentially capable of self-fertilization and hybridization. We have shown previously that reproductive isolation in these species is incomplete in Ea and Ef earthworms of French provenance, as viable offspring appeared in inter-specific pairs. Fertile asymmetric hybrids developed from Ea-derived ova fertilized by Ef-derived spermatozoa, as well as Ea or Ef specimens derived after self-fertilization (resulting from admixture of endogenously produced spermatozoa with sperm from a partner), but never Ef-hybrids from Ef-ova fertilized by Ea-spermatozoa. The latter appeared only in backcrosses of Ea-hybrids with the Ef. Here we show that these phenomena are not unique for French Ea/Ef earthworms, but are shared by earthworms from French, Hungarian, and Polish laboratory cultures. Semi-quantitative studies on fertility of Ea-derived hybrids revealed gradually decreasing numbers of offspring in three successive generations, more rapid in backcrosses with Ef than with Ea, and the absence of progeny in pairs of hybrids, despite the presence of cocoons in almost all pairs. Based on species specific mitochondrial and nuclear DNA sequences, we provide the first examples of two unique sterile hybrids with mitonuclear mismatch and potential mitonuclear incompatibility among offspring of one of the hybrid+Ef pairs. Earthworms from the investigated populations did not reproduce when kept from hatching in isolation or with representatives of Dendrobaena veneta but started reproducing upon recognition of a related partner, such as Ea, Ef or their hybrids. The existence of Ea or Ef specimens among offspring of hybrid+Ea/Ef pairs might be explained either by partner-induced self-fertilization of Ea/Ef or hybrid-derived ova, or by cross-fertilization of Ea/Ef /hybrid ova by partner-derived spermatozoa; the latter might contribute to interspecific gene introgression.

Impaired semen quality in trans women: prevalence and determinants.

STUDY QUESTIONWhat is the semen quality in trans women at time of fertility preservation, prior to the start of gender-affirming hormone treatment?SUMMARY ANSWERBefore the start of gender-affirming hormone treatment, semen quality in trans women was already strongly decreased compared to the general population.WHAT IS KNOWN ALREADYHormone treatment for -trans women (birth-assigned males, female gender identity) consists of anti-androgens combined with estrogens in order to achieve feminization and it is accompanied by a loss of reproductive capability. Trans women can opt for semen cryopreservation prior to their medical transition to retain the possibility to parent genetically related offspring. Post-thaw semen parameters determine which ART can be used. Knowledge of semen quality and the factors negatively influencing semen parameters in trans women are important to improve semen quality before fertility preservation.STUDY DESIGN, SIZE, DURATIONA retrospective cohort study was performed between 1972 and 2017. In total, 260 trans women were included for this study. Due to the study design, there was no loss to follow-up or attrition.PARTICIPANTS/MATERIALS, SETTING, METHODSWe studied the quality of the preserved semen in trans women, prior to their medical transition, who visited our gender clinic. Semen parameters were collected, as well as data on age, alcohol consumption, smoking, cannabis use, BMI, previous use of estrogens or anti-androgens and endocrine laboratory results. Semen parameters were categorized using reference values for human semen of the World Health Organization (WHO) and compared with data from the general population. Logistic regression analyses were performed to analyze the extent to which factors known to have a negative impact on semen quality in the general population explained the impaired semen quality in the cohort.MAIN RESULTS AND THE ROLE OF CHANCEThe cohort consisted of 260 trans women between the age of 16 and 52 years. Semen quality in trans women was significantly decreased compared to WHO data from the general population. In total, 21 trans women had an azoospermia and median semen parameters for the remaining trans women and the general population, respectively, were as follows: volume 2.7 and 3.2 ml (P < 0.05), sperm concentration 40 and 64 million/ml (P < 0.05), total sperm number 103 and 196 million (P < 0.05) and progressive motility 41% and 57% (P < 0.05). Smoking (odds ratio (OR) 2.35 (95% CI 1.06–5.21)) and a higher age at time of fertility preservation (OR 1.04 (95% CI 1.00–1.08)) were found to correlate with an impaired progressive motility. Twelve trans women reported to have used anti-androgens and estrogens, and all had discontinued for at least 3 months prior to the first attempt for semen cryopreservation. No correlation was found between previous gender-affirming hormone use and decreased semen parameters. The median post-thaw total motile sperm count was 1.0 million per vial (interquartile range 0.1–3.1) and in only 26.4% of thawed semen samples was the quality adequate for a minimally invasive IUI.LIMITATIONS, REASONS FOR CAUTIONLimitations include the retrospective design and insufficient data on transgender-specific factors, such as bringing the testes into the inguinal position (tucking), wearing tight underwear and low masturbation frequency.WIDER IMPLICATIONS OF THE FINDINGSSemen quality in trans women was decreased compared to the general population, which could not be explained by known risk factors, such as BMI, alcohol consumption, cannabis use, gender-affirming hormone use or abnormal endocrine laboratory results. Although a negative impact of smoking was observed, it was insufficient to explain the overall decreased semen quality in this cohort. Since low pre-freeze semen quality results in an even lower post-thaw semen quality, the majority of trans women and their female partner or surrogate may need an invasive and burdensome treatment to establish a pregnancy.STUDY FUNDING/COMPETING INTEREST(S)For this study, no external funding was obtained and there were no competing interests.TRIAL REGISTRATION NUMBERNA.

Facile synthesis of nano-nanocarriers from chitosan and pectin with improved stability and biocompatibility for anthocyanins delivery: An in vitro and in vivo study

Anthocyanins is a type of natural pigment with a variety of physiological activities, are unstable and prone to degradation. In order to improve the stability of anthocyanin, in this study, the nanocarriers were constructed through electrostatic self-assembly method using chitosan and pectin as raw materials for bilberry anthocyanins delivery. Atomic force microscope and scanning electron microscope analyses showed that the nanocarriers were well dispersed spheres with diameters around 100–300 nm when the mass ratio of chitosan/pectin/anthocyanin was 1:1:3. Fourier transform infrared spectroscopy and ultraviolet–visible absorption spectroscopy results revealed that the anthocyanins were successfully doped into the nanocarriers. The encapsulation efficiency of anthocyanins was 66.68%. Moreover, the anthocyanin nanocarriers exhibited increased storage stability under light and dark conditions. In vitro digestion experiments showed that the doped anthocyanins could escape from the interference of stomach acid environment and released slowly in small intestinal fluid, suggesting the controlled delivery of anthocyanins in the gastrointestinal tract. In vitro NRK cell model demonstrated that the nanocarriers could protect against acrylamide-induced damage by viability and cell apoptosis assay. In vivo Caenorhabditis elegans model further showed that the nanocarriers could protect from anthocyanin damage caused by various harmful conditions such as acrylamide, oxidative stress, heat shock and UV light. Furthermore, Caenorhabditis elegans treated with nanocarriers showed longer lifespan, stronger reproductive capability, more flexible locomotion behavior, and less autofluorescent lipofuscin particles. Together, these results suggest that chitosan-pectin nanoparticles can be used as delivery vehicles to improve the stability and bioavailability of the functional factor anthocyanin.

Hormonal profile of Mediterranean green turtles (Chelonia mydas)

The beaches of Turkey are important nesting habitats of Chelonia mydas sea turtles and the determination of their health and disease status is critical in sustaining healthy populations. Limited data currently exist on the hormone values required to determine the status of reproductive capabilities of sea turtles. This study aimed to collect basic data regarding their hormonal profile and set reference limits for the Mediterranean population. Forty-nine free-ranging C. mydas sea turtles were used in the study and were classified into 3 groups according to their age (hatchlings, juvenile, adult). Adult turtles were also grouped according to sex. Adult females were further divided into 3 seasonal groups (summer, spring, and autumn), based on the dates of blood sampling. Plasma testosterone, oestradiol, progesterone, thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), cortisol, and corticosterone levels were determined by ELISA method. Significantly higher levels were observed in oestrogen (P < 0.001), progesterone (P < 0.001), cortisol (P < 0.05), corticosterone (P < 0.05), T3 (P < 0.05), and T4 (P < 0.01) in the adult turtles when compared with the other groups. The highest levels of oestrogen (280.2 ± 39.34), progesterone (274.2 ± 29.4), cortisol (2.26 ± 0.36), and corticosterone (2.94 ± 0.53) were determined in the adult female turtles during the spring season. This data could be used to protect the population of this endangered species by taking precautions against diseases via determining their blood hormone levels and taking precautions against reproductive diseases. Further work is required, but this research can expand the knowledge on the basic blood biochemistry of Mediterranean green turtles.

Functional reconstruction of injured corpus cavernosa using 3D-printed hydrogel scaffolds seeded with HIF-1\u03b1-expressing stem cells

Injury of corpus cavernosa results in erectile dysfunction, but its treatment has been very difficult. Here we construct heparin-coated 3D-printed hydrogel scaffolds seeded with hypoxia inducible factor-1α (HIF-1α)-mutated muscle-derived stem cells (MDSCs) to develop bioengineered vascularized corpora. HIF-1α-mutated MDSCs significantly secrete various angiogenic factors in MDSCs regardless of hypoxia or normoxia. The biodegradable scaffolds, along with MDSCs, are implanted into corpus cavernosa defects in a rabbit model to show good histocompatibility with no immunological rejection, support vascularized tissue ingrowth, and promote neovascularisation to repair the defects. Evaluation of morphology, intracavernosal pressure, elasticity and shrinkage of repaired cavernous tissue prove that the bioengineered corpora scaffolds repair the defects and recover penile erectile and ejaculation function successfully. The function recovery restores the reproductive capability of the injured male rabbits. Our work demonstrates that the 3D-printed hydrogels with angiogenic cells hold great promise for penile reconstruction to restore reproductive capability of males.

Ectopic over expression of kiss1 may compensate for the loss of kiss2

Kisspeptin (KISS) is a neuropeptide which plays a central role in the regulation of the hypothalamic-pituitary–gonadal axis, and is essential for sexual maturation and fertility in mammals. Unlike mammals, which possess only one KISS gene, two paralogous genes, kiss1 and kiss2, have been identified in zebrafish and other non-mammalian vertebrates. Previous studies suggest that Kiss2, but not Kiss1, is the reproduction relevant form amongst the two. To better understand the role of each of these isoforms in reproduction, a loss of function approach was applied. Two genetic manipulation techniques—clustered regularly interspaced short palindromic repeats (CRISPR) and transcription activator-like effector nucleases (TALEN)—were used to generate kiss1 and kiss2 knockout (KO) zebrafish lines, respectively. Examination of these KO lines showed that reproductive capability was not impaired, confirming earlier observations. Further analysis revealed that KO of kiss2 caused a significant increase in expression levels of kiss1, kiss2r and tac3a, while KO of kiss1 had no effect on the expression of any of the examined genes. In situ hybridization analysis revealed that kiss1 mRNA is expressed only in the habenula in wild type brains, while in kiss2 KO fish, kiss1 mRNA-expressing cells were identified also in the ventral telencephalon, the ventral part of the entopeduncular nucleus, and the dorsal and ventral hypothalamus. Interestingly, these regions are known to express kiss2r, and the ventral hypothalamus normally expresses kiss2. These results suggest that a compensatory mechanism, involving ectopic kiss1 expression, takes place in the kiss2 KO fish, which may substitute for Kiss2 activity.

Providing Patient-centered Perinatal Care for Transgender Men and Gender-diverse Individuals: A Collaborative Multidisciplinary Team Approach

(Obstet Gynecol. 2019;134:959–963) Over the course of the last decade, the experience of pregnancy in transgender men (and other gender-diverse people who were assigned female sex at birth) has secured higher visibility within medical journals. While some gender-affirming treatments eliminate fertility, such as hysterectomy or oophorectomy, some transgender men may retain or even desire reproductive capability. Both intended and unintended pregnancies after undergoing gender-affirming processes have occurred, and some transgender men aspire for subsequent pregnancy and parenthood depending on their stage of transition and age. As there is little clinical guidance for medical care from prenatal to postpartum, this is a divulsion of a case intended to help create a more equitable and inclusive health care experience for transgender men and to assure patient-centered care.

SUN-LB57 Assessing the Requirement of Arcuate Nucleus Kisspeptin Neurons in Puberty Onset and Adult LH Secretion

Puberty is a critical developmental period marking the transition to adulthood and attainment of reproductive capability. A hallmark of puberty is increased pulsatile secretion of pituitary luteinizing hormone (LH) which is itself driven by increased gonadotropin-releasing hormone (GnRH) from the forebrain. The mechanisms governing GnRH neuron activation at puberty still remain unclear, but likely include enhanced stimulation from upstream reproductive neural circuits, including kisspeptin neurons. Kisspeptin is a potent stimulator of GnRH and is required for proper puberty onset. However, the specific brain site(s) from where kisspeptin signaling arises to trigger puberty remain unclarified. Kisspeptin is expressed in two primary nuclei in the hypothalamus, the arcuate nucleus (ARC) and anteroventral periventricular (AVPV) region. Studies suggest that, in adulthood, ARC Kiss1 neurons are involved in driving pulsatile secretion of GnRH (and hence, LH) in both sexes whereas AVPV Kiss1 neurons participate in the preovulatory GnRH/LH surge in females. However, the specific role of either kisspeptin neuron population in puberty onset still remains unknown. We previously showed that both kisspeptin populations show increased Kiss1 gene expression across the pubertal period, yet whether just one or both (or neither) population is needed for puberty to occur has not been determined. Here, we sought to tease out the role—if any—of ARC and AVPV Kiss1 neurons in the pubertal onset process. Since ARC Kiss1 neurons are abundant in both sexes and drive pulsatile GnRH secretion in adulthood, we hypothesized that ARC Kiss1 neurons are necessary for normal puberty onset and, conversely, that AVPV Kiss1 neurons are not sufficient on their own to induce normal puberty. To test this hypothesis, we used a Cre-specific diphtheria toxin approach to ablate just ARC Kiss1 neurons in juvenile mice (~ 2 weeks old) while leaving AVPV Kiss1 neurons intact. Preliminary data thus far indicates that site specific ablation of just ARC Kiss1 neurons during the juvenile period significantly delays puberty onset in both sexes, as measured by vaginal opening, first estrous, and preputial separation. In addition, selective ARC Kiss1 neuron ablation in juvenile life diminishes pulsatile LH secretion levels measured in adulthood, but does not alter LH surge generation in adult females. These preliminary findings empirically demonstrate that, in mice, ARC Kiss1 neurons are required for proper activation of the reproductive axis during puberty but not the LH surge in adulthood, and AVPV Kiss1 neurons are not sufficient to trigger normal pubertal onset.

Infertility among iron industry workers

Occupational exposures in different industries may pose serious health impacts. A number of epidemiological studies have focused on the association of occupational exposures and adverse health effects. The need of the hour is to focus on the reproductive health of workers engaged at different jobs in varied industries. Increasing environmental as well as occupational exposures have led to serious effects on the reproductive health of workers and have also endangered the life of future generations. The present paper highlights the impact of occupational exposures on iron industry workers. Future health based researches are recommended so as to assess the impact of occupational exposures on reproductive capabilities of workers.

KEMAMPUAN REPRODUKSI INDUK DAN PERTUMBUHAN ANAK KAMBING PERANAKAN ETAWAH, GEMBRONG, DAN KOSTA

Indonesia has various types of local goat germplasm like a goat Peranakan Etawah (PE), Gembrong, and Kosta. Information of those local goats including the parent reproduction and kids productivity are still limited. Study aims to evaluate maternal reproduction capability and kids productivity of goat PE, Gembrong, and Kosta. Study was conducted in 24 does and 44 kids of PE, Gembrong, and Kosta in Loka Kambing Potong (Goat Research Station), Sumatera Utara. A goat mated with of the study from each the goat breed. Data of reproduction were collected from mating to calving. Data of kids productivity were collected from birth to nine month-old. As reproductive capability data, the highest litter size and type of birth were demonstrated in goat PE. Goat gembrong produced more male, whereas goat Kosta had shorter pregnant duration than other goats. Birth weight of PE was significantly different (p 0.05). Pre-weaning and post-weaning mortality was highest in Kosta.

A theory of the aims and objectives of midwifery practice: A theory synthesis

IntroductionEvery discipline has a dichotomous objective by which it recognizes whether its work has been successful (Vogd, 2011). For midwifery care, no objective has been set in this way so far. This also has implications for measuring quality, because quality of care is only measurable if objectives have been identified. This paper aims to contribute to theory formation in midwifery science by analysing existing concepts and theories and preferences of women to midwifery care to answer the question of the dichotomous objective of midwifery. Method and findingsThe method of theory synthesis (Walker and Avant, 2011) was used to analyse existing theories and concepts of midwifery care and literature-based preferences of women to midwifery care and synthesize them with regard to the objectives of midwifery care. The synthesis took place in the form of a means-end chain to extract the dichotomous target of midwifery care. In this way, the objectives of midwifery could be compared and linked from both the scientific and from women's perspective. The resulting means-end chain model of the process of midwifery describes the aims and objectives of midwifery from the point of view of women on three levels. DiscussionThe hierarchical model of the process of midwifery presented here is a first attempt to illustrate the aims and objectives of midwifery practice in a means-end chain model in order to facilitate discussion on the topic and to make the quality of midwifery care measurable. Measurement is a first step towards improving quality of midwifery care and thereby improving women's reproductive capabilities.

The impact of elevated temperature and CO2 on growth, physiological and immune responses of Polypedates cruciger (common hourglass tree frog)

BackgroundAmphibians are one of the most susceptible groups to climate change as their development occurs in aquatic environments or in microhabitats with high humidity. Accordingly, our primary objective was to investigate the chronic physiological responses seen in early larval to adult stages of Polypedates cruciger (Common hourglass tree frog) to future climate change based on continuous exposure to elevated temperature and elevated CO2 -induced low water pH. Free-swimming and free-feeding tadpoles were observed until metamorphosis under four experimental treatments; two elevated temperatures, one elevated CO2 (reduced pH) and a control maintained at ambient temperature (29 °C ± 1 °C) and CO2 (pH = 7). Elevated temperature treatments were maintained at 32 °C ± 0.5 °C and 34 °C ± 0.5 °C to represent respectively, the future climate scenarios RCP2.6 (Representative Concentration Pathway 2.6, the ‘base-case’ scenario) and RCP8.5 (‘business-as-usual’ scenario) according to the 5th Assessment Report of the IPCC. Elevated CO2 treatment was maintained within the pH range of 5.5–5.6 representing the range expected between RCP8.5 and RCP2.6.ResultsCompared to the control, elevated CO2 accelerated phenological progression of tadpoles through Gosner stages, thus resulting in lower body size at metamorphosis. Both elevated temperatures significantly delayed the development and reduced the growth of tadpoles. 100% mortality was observed in 34 °C treatment before metamorphosis (before Gosner stage 36) while all the tadpoles died after metamorphosis (at Gosner stage 46) in 32 °C treatment. Elevated CO2 increased tadpole activity, in terms of their swimming speed, while both of the elevated temperatures reduced it compared to the control. Catalase activity increased at elevated CO2. Ammonia excretion by tadpoles was decreased by elevated CO2, but increased under temperature elevation. Both Elevated CO2 and temperature treatments reduced the white blood cell count and its percentage of thrombocytes. Percentages of lymphocytes, monocytes and neutrophils were increased at 32 °C, while lymphocyte percentage and lysozyme activity were increased at elevated CO2. Several deformities were observed in tadpoles at elevated temperature and CO2.ConclusionsElevated temperatures and reduced pH due to elevated CO2, being major features of climate change, increase the vulnerability of amphibians, who are already one of the most threatened vertebrate groups. Based on our observations on the model amphibian species P. cruciger, increased vulnerability to climate change occurs by reducing their growth, body size and motility while also reducing their immunity and inducing physical deformities. These impacts are highly-likely to reduce the foraging, competitive and reproductive capabilities in their natural habitats. We conclude further that even the ‘best-case’ scenario of future climate change can impose significant physiological impacts that could threaten amphibian populations on broader spatial and temporal scales.Graphical abstract

Separate seasons of infection and reproduction can lead to multi-year population cycles

Many host–pathogen systems are characterized by a temporal order of disease transmission and host reproduction. For example, this can be due to pathogens infecting certain life cycle stages of insect hosts; transmission occurring during the aggregation of migratory birds; or plant diseases spreading between planting seasons. We develop a simple discrete-time epidemic model with density-dependent transmission and disease affecting host fecundity and survival. The model shows sustained multi-annual cycles in host population abundance and disease prevalence, both in the presence and absence of density dependence in host reproduction, for large horizontal transmissibility, imperfect vertical transmission, high virulence, and high reproductive capability. The multi-annual cycles emerge as invariant curves in a Neimark–Sacker bifurcation. They are caused by a carry-over effect, because the reproductive fitness of an individual can be reduced by virulent effects due to infection in an earlier season. As the infection process is density-dependent but shows an effect only in a later season, this produces delayed density dependence typical for second-order oscillations. The temporal separation between the infection and reproduction season is crucial in driving the cycles; if these processes occur simultaneously as in differential equation models, there are no sustained oscillations. Our model highlights the destabilizing effects of inter-seasonal feedbacks and is one of the simplest epidemic models that can generate population cycles.

A proteomics analysis of the ovarian development in females of Haemaphysalis longicornis.

Haemaphysalis longicornis is an ixodid tick that can spread a wide variety of pathogens, affecting humans, livestock and wildlife health. The high reproductive capability of this species is initiated by the ingestion of a large amount of blood ingested by the engorged female tick. The degree of ovarian development is proportional to the number of eggs laid. Studying the regulatory mechanism of tick ovary development is relevant for the development of novel tick control methods. In this study, we used quantitative proteomics to study the dynamic changes in protein expression and protein phosphorylation during ovarian development of engorged female H. longicornis ticks. Synergistic action of many proteins (n = 3031) is required to achieve ovarian development and oocyte formation rapidly. Through bioinformatics analysis, changes in protein expressions and phosphorylation modifications in regulating the ovarian development of female ticks are described. Many proteins play an essential role during ovarian development. Also, protein phosphorylation appeared an important reproductive strategy to enable ticks to efficiently convert large amounts of blood in the ovaries into egg-producing components and ultimately produce many eggs.

Cushing's Disease in Children: A Review.

Cushing's disease is rare in the paediatric age group. The disease manifestations are similar to that seen in adults. Most of the management protocols have, therefore, been adopted from experience in adults and the therapeutic strategies employed in the latter group. Management of paediatric Cushing's disease poses significant challenges with regard to achieving an optimal growth, a proper body composition, an adequate bone health and reproductive capability as well as a good quality of life. This article reviews the special clinical, biochemical, radiological, surgical, and adjunctive therapeutic considerations in paediatric Cushing's disease.

INSEMINATION INDEX AND FERTILIZATION SUCCESS IN HOLSTEIN`S CATTLE RACE AFTER RETENTION OF THE PLACENTA

Reproductive capabilities are significant economic characteristics and they are given special attention and strives to maintain at a satisfactory level or even improve by different zootechnical measures. Reproduction in Holstein cows is an introduction to production and are indirectly linked, and better reproductive characteristics in cows also give positive economic effects. Significant reproductive characteristics are the index of insemination and the success of insemination after calving. The research work was based on proving the effect of residual placenta and its retention on the mentioned reproductive properties. The first group of cows X1 consisted of cows with normal calves and numbered 34 cows, and were characterized by on time plunged placenta, with an average index of insemination of 1.2. The insemination index in the group of cows X2 containing 20 cows with residual placenta, and where reteniting of placenta was up to 30 hours after calving, was 2.1. The largest oscillation index had a group of cows X3 that counted 14 heads, where the placenta retention was made after 30 hours from the calving moment with a 4.86 index. Detailed analysis of the insemination index showed the data for the success rate of insemination, for the group X1 from the first attempt was 79.41% and from the second was 20.59%. Group X2 has an insemination performance for the first attempt of 45.0%, the second attempt was 30.0%, the third 10.0% and the fourth was 15.0%. Cows that have placental retention after 30 hours of calving, X3, the success rate of insemination is very low, and for the first attempt it was 14.3%, the second and the third to 7.15% while for the fourth and subsequent attempts was 50.0%. The best reproductive indicators had a group of cows with normal calves and calves removed on time.