Browsing by Author "Kaya, A."

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KÜRESELLEŞME SONRASI YENİ TİP KRİZLER: COVID-19 ÖZELİNDE BİR DEĞERLENDİRME
(2023) Kaya, A.
Küreselleşmeyle beraber dünyada yaşanan krizler dönüşüme uğramaya başlamıştır. Emek ve sermaye hareketliliğinin yaygınlaşması, ulaşım ve iletişim maliyetlerinin azalması gibi birçok açıdan sağladığı faydaların yanında küreselleşmenin yol açtığı yeni tip krizler de mevcuttur. Yeni tip krizlere en önemli örneklerden biri finans piyasalarında yaşanan krizlerdir. Özellikle küreselleşmenin hız kazandığı 1990’lardan itibaren sermaye hareketliliğinin artışıyla finans alanında yaşanan krizlerin yaygınlaşarak birçok ülkeyi etkisi altına alması küreselleşme sonrası yeni tip krizlerin boyutunu göstermektedir. Finans krizleri haricinde yeni tip krizlere verilebilecek en güzel örneklerden biri de salgın hastalıklar olarak görülmektedir. Ulaşım teknolojisindeki gelişmelerle beraber insanın ve emek faktörünün hareketliliği artmakta, salgın hastalıklar geçmişte olmadığı kadar hızlı bir biçimde yayılmakta ve neredeyse bütün dünyayı etkilemektedir. Bu hastalıkların en günceli ise Covid-19 salgınıdır. Bu salgın, ekonomik, siyasi ve sosyal yönden dünyadaki hemen hemen her ülkeyi olumsuz şekilde etkilemiştir. Bu salgınla beraber liberal ekonomi politikaları ve serbest piyasa rejimi sorgulanmaya başlanmış, devletçi politikalar önem kazanmıştır. Meşruluğu tartışılmaya başlanan ulus devletler bu krizden güçlü şekilde çıkmıştır. Ulus devletlerin uygulamış olduğu maliye politikaları krizden çıkış için önemli bir adım olmuştur. Ayrıca krizin etkilerini bertaraf edebilmek ve krizin etkisiyle bozulan gelir dağılımını düzeltebilmek için servet vergileri tekrar gündeme getirilmiştir.
Melatonin Protects Bovine Embryos from Heat Stress and Oxygen Tension and Improves Embryo Production In vitro
(2023.01.01) Hitit, M.; Schindler, J.; Memili, E.; Parrish, J.J.; Kaya, A.
The objective of this study was to determine melatonin's ameliorating effects against heat stress and oxygen tension in developing bovine embryos in vitro. The oocytes were collected from ovaries obtained from a local abattoir, followed by in vitro maturation, fertilization, and embryo culture. During in vitro culture, embryos were exposed to 5% (Group I) and 20% (Group II) oxygen tension with 10(-3), 10(-6), and 10(-9) molar (M) melatonin, along with the control group without melatonin (Group III). Compared to the control group, melatonin at 10(-6) and 10(-9) concentrations increased in vitro development rates and decreased caspase 3/7 activity at 5% and 20% oxygen tension (P<0.01). Onehalf of the zygotes were cultured under normal temperature (38.5degree celsius) during the culture period, and the other half of the zygotes were heat stressed at 41degree celsius for six hours. Then they transferred into the normal culture conditions for the rest of the period using 0, 10(-6), and 10(-9) M of melatonin (Group IV). Under normal temperature (38.5degree celsius), melatonin at 10(-9) M was beneficial for in vitro development and DNA integrity. Under heat stress at 41degree celsius, melatonin at 10(-6) and 10(-9) M was useful for in vitro development and DNA integrity (P<0.05). Supplementation of melatonin to embryo culture medium did not alter the caspase 3 and 7 activities (P>0.05). In conclusion, melatonin prevents the adverse effects of heat stress and O-2 tension on preimplantation bovine embryos in vitro.
Sperm long non-coding RNAs as markers for ram fertility
(2024) Hitit, M.; Kaya, A.; Memili, E.
It is critical in sheep farming to accurately estimate ram fertility for maintaining reproductive effectiveness and for production profitability. However, there is currently a lack of reliable biomarkers to estimate semen quality and ram fertility, which is hindering advances in animal science and technology. The objective of this study was to uncover long non-coding RNAs (lncRNAs) in sperm from rams with distinct fertility phenotypes. Mature rams were allocated into two groups: high and low fertility (HF; n = 31; 94.5 ± 2.8%, LF; n = 25; 83.1 ± 5.73%; P = 0.028) according to the pregnancy rates sired by the rams (average pregnancy rate; 89.4 ± 7.2%). Total RNAs were isolated from sperm of the highest- and lowest-fertility rams (n = 4, pregnancy rate; 99.2 ± 1.6%, and 73.6 ± 4.4%, respectively) followed by next-generation sequencing of the transcripts. We uncovered 11,209 lncRNAs from the sperm of rams with HF and LF. In comparison to each other, there were 93 differentially expressed (DE) lncRNAs in sperm from the two distinct fertility phenotypes. Of these, 141 mRNAs were upregulated and 134 were downregulated between HF and LF, respectively. Genes commonly enriched for 9 + 2 motile cilium and sperm flagellum were ABHD2, AK1, CABS1, ROPN1, SEPTIN2, SLIRP, and TEKT3. Moreover, CABS1, CCDC39, CFAP97D1, ROPN1, SLIRP, TEKT3, and TTC12 were commonly enriched in flagellated sperm motility and sperm motility. Differentially expressed mRNAs were enriched in the top 16 KEGG pathways. Targets of the differentially expressed lncRNAs elucidate functions in cis and trans manner using the genetic context of the lncRNA locus, and lncRNA sequences revealed 471 mRNAs targets of 10 lncRNAs. This study illustrates the existence of potential lncRNA biomarkers that can be implemented in analyzing the quality of ram sperm and determining the sperm fertility and is used in breeding soundness exams for precision livestock farming to ensure food security on a global scale.
Sperm long non-coding RNAs as markers for ram fertility
(2024.01.01) Hitit, M.; Kaya, A.; Memili, E.
It is critical in sheep farming to accurately estimate ram fertility for maintaining reproductive effectiveness and for production profitability. However, there is currently a lack of reliable biomarkers to estimate semen quality and ram fertility, which is hindering advances in animal science and technology. The objective of this study was to uncover long non-coding RNAs (lncRNAs) in sperm from rams with distinct fertility phenotypes. Mature rams were allocated into two groups: high and low fertility (HF; n = 31; 94.5 +/- 2.8%, LF; n = 25; 83.1 +/- 5.73%; P = 0.028) according to the pregnancy rates sired by the rams (average pregnancy rate; 89.4 +/- 7.2%). Total RNAs were isolated from sperm of the highest- and lowest-fertility rams (n = 4, pregnancy rate; 99.2 +/- 1.6%, and 73.6 +/- 4.4%, respectively) followed by next-generation sequencing of the transcripts. We uncovered 11,209 lncRNAs from the sperm of rams with HF and LF. In comparison to each other, there were 93 differentially expressed (DE) lncRNAs in sperm from the two distinct fertility phenotypes. Of these, 141 mRNAs were upregulated and 134 were downregulated between HF and LF, respectively. Genes commonly enriched for 9 + 2 motile cilium and sperm flagellum were ABHD2, AK1, CABS1, ROPN1, SEPTIN2, SLIRP, and TEKT3. Moreover, CABS1, CCDC39, CFAP97D1, ROPN1, SLIRP, TEKT3, and TTC12 were commonly enriched in flagellated sperm motility and sperm motility. Differentially expressed mRNAs were enriched in the top 16 KEGG pathways. Targets of the differentially expressed lncRNAs elucidate functions in cis and trans manner using the genetic context of the lncRNA locus, and lncRNA sequences revealed 471 mRNAs targets of 10 lncRNAs. This study illustrates the existence of potential lncRNA biomarkers that can be implemented in analyzing the quality of ram sperm and determining the sperm fertility and is used in breeding soundness exams for precision livestock farming to ensure food security on a global scale.
The potential protective effects of melatonin and omega-3 on the male rat optic nerve exposed to 900?MHz electromagnetic radiation during the prenatal period
(2023.01.01) Tuefekci, K.K.; Kaplan, A.A.; Kaya, A.; Alrafiah, A.; Altun, G.; Aktas, A.; Kaplan, S.
Background: Due to children and adolescents' widespread use of electronic devices, researchers have focused on pre-and early postnatal electromagnetic field (EMF) exposure. However, little is known about the effects of EMF exposure on the optic nerve. The aim of study was to investigate the changes occurring in the optic nerve and the protective effects of melatonin (mel) and omega 3 (?-3) in rats.Methods: Thirty-five pregnant rats were divided into seven groups, Cont, Sham, EMF, EMF + melatonin (EMF + Mel), EMF + ?3, Mel, and ?3. The EMF groups were exposed to 900 megahertz (MHz) EMF daily for two hours during pregnancy. After the experiment, the right optic nerve of each offspring rat was removed and fixed in glutaraldehyde. Thin and semi-thin sections were taken for electron microscopic and stereological analyses. Myelinated axon numbers, myelin sheath thicknesses, and axonal areas were estimated using stereological methods.Results: The groups had no significant differences regarding mean numbers of axons, mean axonal areas, or mean myelin sheath thicknesses (p > 0.05). Histological observations revealed impaired lamellae in the myelin sheath of most axons, and vacuolization was frequently observed between the myelin sheath and axon in the EMF-exposed group. The Mel and ?-3-treated EMF groups exhibited well-preserved myelinated nerve fibers and intact astrocytes and oligodendrocytes.Conclusions: At the ultrastructural level, Mel and ?3 exhibits a neuroprotective effect on the optic nerve exposed to prenatal EMF. The protective effects of these antioxidants on oligodendrocytes, which play an essential role in myelin formation in the central nervous system, now require detailed investigation.
Uterus stereology
(Nova Science Publishers, Inc., 2024) Kaya, A.; Altun, G.; Tüfekçi, K.K.; Kaplan, A.A.; Kipanyula, M.J.; Kaplan, S.
Infertility is a growing global health problem with important socio-psychological consequences. The main causes of infertility are the pathogenesis of the uterine mucosa and the uterus being unready for implantation as a result of decidualization. Despite the critical importance of the uterus for women's health and fertility, and embryo development, relatively limited information is available concerning the hormonal, cellular, and molecular mechanisms in its pathogenesis. Morphoquantitative assessments are widely used by researchers to explain the underlying causes of infertility. Quantitative evaluations provide more descriptive and precise information when observing structural changes in tissue under different conditions and comparing these between different groups. Design-based stereology provides an accurate and unbiased estimation of stereological parameters, avoiding sources of bias caused by the methodology employed. It is therefore important to use stereological methods when considering a quantitative morphological evaluation of biological objects. This chapter describes the importance of developing and disseminating the use of stereological techniques in uterine research and is intended to explain the modern stereological techniques applied to uterine tissue in methodological terms.