scholarly journals Torpor expression is associated with differential spermatogenesis in hibernating eastern chipmunks

2020 ◽  
Vol 319 (4) ◽  
pp. R455-R465
Author(s):  
Marianne F. Gagnon ◽  
Christine Lafleur ◽  
Manuelle Landry-Cuerrier ◽  
Murray M. Humphries ◽  
Sarah Kimmins
Keyword(s):  
Dna Damage ◽  
Spermatogenic Cells ◽  
Sperm Production ◽  
Physiological Processes ◽  
Data Loggers ◽  
Sperm Counts ◽  
Low Levels ◽  
Potential Impact ◽  
Eastern Chipmunks ◽  
The Relationship

Hibernators suppress physiological processes when expressing torpor, yet little is known about the effects of torpor on male reproductive physiology. Studies of hibernating mammals suggest that deep torpor negatively impacts spermatogenesis and that transitions between torpor and euthermic arousals increase cellular oxidative stress, with potentially damaging effects on sperm. Here, we hypothesize that variation in torpor expression affects the reproductive readiness of hibernators by impacting their sperm production. To test this, we examined the relationship between torpor expression and spermatogenesis in captive eastern chipmunks ( Tamias striatus). We determined torpor depth with temperature data loggers and assessed its relationship with spermatogenesis by examining spermatogenic progression, cell division, sperm counts, sperm maturity, and DNA damage. We show that deep hibernators (high levels of torpor) largely halted spermatogenesis in late hibernation in comparison with shallow hibernators (low levels of torpor), where ongoing spermatogenesis was observed. Despite these differences in spermatogenic state during hibernation, spermatogenic progression, sperm numbers, and maturity did not differ in spring, potentially reflecting similar degrees of reproductive readiness. Interestingly, shallow hibernators exhibited higher rates of DNA damage in spermatogenic cells during hibernation, with this trend reversing in spring. Our results thus indicate that once heterothermy is terminated, deep hibernators resume spermatogenesis but are characterized by higher rates of DNA damage in spermatogenic cells at the seasonal stage when spring mating commences. Therefore, our study confirmed posthibernation recovery of sperm production but also a potential impact of deep torpor expression during winter on DNA damage in spring.

Rapid recovery of spermatogenesis after mitoxantrone, vincristine, vinblastine, and prednisone chemotherapy for Hodgkin's disease.

1997 ◽  
Vol 15 (12) ◽  
pp. 3488-3495 ◽  
Author(s):  
M L Meistrich ◽  
G Wilson ◽  
K Mathur ◽  
L M Fuller ◽  
M A Rodriguez ◽  
...  
Keyword(s):  
Hodgkin's Disease ◽  
Male Fertility ◽  
Sperm Count ◽  
Hodgkin’S Disease ◽  
Spermatogenic Cells ◽  
Sperm Production ◽  
Human Male ◽  
Sperm Counts ◽  
Abdominal Radiotherapy ◽  
Upper Abdominal

PURPOSE Because the effects of mitoxantrone on human male fertility were unknown, we determined prospectively the effects of three courses of mitoxantrone (Novantrone), vincristine (Oncovin), vinblastine, prednisone (NOVP) chemotherapy on the potential for fertility of men with Hodgkin's disease (HD). PATIENTS AND METHODS Semen analyses were performed on 58 patients with stages I-III HD before, during, and after chemotherapy and after the sperm count recovered from the effects of abdominal radiotherapy that was given after chemotherapy. RESULTS Before the initiation of treatment, 84% of the patients were normospermic. Sperm counts declined significantly within 1 month after the start of NOVP chemotherapy. In the month after chemotherapy, 38% of patients were azoospermic, 52% had counts < 1 million/ mL, and 10% had counts between 1 and 3 million/mL. Between 2.6 and 4.5 months after the completion of chemotherapy, sperm counts recovered rapidly to normospermic levels in 63% of patients. In the remaining patients who were followed up for at least 1 year after standard upper abdominal radiotherapy, counts also recovered to normospermic levels. CONCLUSION NOVP chemotherapy, like most other regimens, produced marked temporary effects or spermatogenesis. However, sperm production recovered very rapidly, within 3 to 4 months after the end of NOVP chemotherapy. This pattern was caused by killing differentiating spermatogenic cells, but there was little cytotoxicity or inhibition of stem cells from mitoxantrone or the other drugs. After the combination of NOVP plus abdominal radiotherapy, sperm counts and motility were restored in most patients to pretreatment levels, which were compatible with normal fertility.

scholarly journals Hubungan antara Tingkah Laku Seksual dengan Produksi Spermatozoa Sapi Brahman

2018 ◽  
Vol 18 (2) ◽  
pp. 67-73
Author(s):  
Nisa'us Sholikah ◽  
Aris Sutomo ◽  
Ndaru Pranowo Widiasmoro ◽  
Sri Wahjuningsih ◽  
Aulia Puspita Anugra Yekti ◽  
...  
Keyword(s):  
Sexual Behavior ◽  
Reaction Time ◽  
Volume Concentration ◽  
Pearson Correlation ◽  
Coefficient Of Determination ◽  
Motile Sperm ◽  
Sperm Production ◽  
Sperm Counts ◽  
The Relationship ◽  
Artificial Vagina

ABSTRAK. Pejantan untuk program inseminasi buatan adalah pejantan unggul yang diseleksi berdasarkan libido dan produksi spermatozoa. Penelitian bertujuan untuk menganalisa hubungan antara tingkah laku seksual dengan produksi spermatozoa sapi Brahman. Materi penelitian adalah 3 pejantan sapi Brahman yang ditampung menggunakan vagina buatan. Metode penelitian adalah observasional dengan mengamati waktu reaksi dan lama ejakulasi. Observasi laboratorium dengan mengamati volume, konsentrasi, dan motilitas individu untuk menghitung total spermatozoa (TS) dan total spermatozoa motil (TSM). Pengamatan dilakukan sebanyak 10 ulangan. Data dianalisa secara deskriptif serta hubungan antara tingkah laku seksual dan produksi spermatozoa dihitung dengan korelasi Pearson. Hasil penelitian menunjukkan terdapat variasi tingkah laku seksual dan produksi spermatozoa pada sapi Brahman. Individu Cipta mempunyai waktu reaksi dan lama ejakulasi paling singkat serta produksi spermatozoa paling rendah. Hubungan signifikan antara waktu reaksi dengan TS serta TSM pada individu Bizzyard dengan koefisien determinasi (R2) sebesar 14 % dan 20%. Hubungan sangat signifikan antara lama ejakulasi dengan TS serta TSM pada individu Cipta dengan R2 sebesar 46% dan 58%. Kesimpulan penelitian adalah terdapat hubungan antara tingkah laku seksual dengan produksi spermatozoa pada sapi Brahman, dengan koefisien korelasi (r) tertinggi sebesar 0,72 dan R2 sebesar 58% antara lama ejakulasi dan total spermatozoa motil pada individu Cipta.  (The relationship between sexual behavior and semen production in Brahman bulls) ABSTRACT. Bulls for artificial insemination must be selected based on libido and sperm production. The study aimed to analyze the relationship between sexual behavior with sperm production on Brahman bulls. The material was 3 Brahman bulls collected using artificial vagina. The method was observational by observing reaction time and ejaculation duration. Laboratory observations by observing volume, concentration, and motility to calculate total sperm (TS) and total motile sperm counts (TMSC). Observations were replicated 10 times. The data were analyzed descriptively, the relationship between behavior and sperm production was examined using Pearson correlation. The results showed that there were variations in sexual behavior and sperm production in each bull. Cipta have the shortest reaction time and ejaculation duration and the lowest sperm production. A significant relationship between reaction time and TS and TMSC in Bizzyard with coefficient of determination (R2) of 14% and 20%. A very significant between ejaculation duration with TS and TMSC in Cipta with R2 of 46% and 58%. In conclusion, there was a relationship between sexual behavior and sperm production in Brahman bulls, with the highest correlation coefficient (r) of 0.72 and R2 of 58% between ejaculation duration and the total motile sperm counts in Cipta.

Exploring the Potential Impact of Sentence-Level Comprehension and Sentence-Level Fluency on Deaf Students' Passage Comprehension

2020 ◽  
Vol 63 (7) ◽  
pp. 2281-2292
Author(s):  
Ying Zhao ◽  
Xinchun Wu ◽  
Hongjun Chen ◽  
Peng Sun ◽  
Ruibo Xie ◽  
...  
Keyword(s):  
Independent Predictor ◽  
Vocabulary Knowledge ◽  
Group Differences ◽  
Regression Analyses ◽  
Deaf Students ◽  
Mediating Role ◽  
Sentence Level ◽  
Mediating Mechanisms ◽  
Potential Impact ◽  
The Relationship

Purpose This exploratory study aimed to investigate the potential impact of sentence-level comprehension and sentence-level fluency on passage comprehension of deaf students in elementary school. Method A total of 159 deaf students, 65 students ( M age = 13.46 years) in Grades 3 and 4 and 94 students ( M age = 14.95 years) in Grades 5 and 6, were assessed for nonverbal intelligence, vocabulary knowledge, sentence-level comprehension, sentence-level fluency, and passage comprehension. Group differences were examined using t tests, whereas the predictive and mediating mechanisms were examined using regression modeling. Results The regression analyses showed that the effect of sentence-level comprehension on passage comprehension was not significant, whereas sentence-level fluency was an independent predictor in Grades 3–4. Sentence-level comprehension and fluency contributed significant variance to passage comprehension in Grades 5–6. Sentence-level fluency fully mediated the influence of sentence-level comprehension on passage comprehension in Grades 3–4, playing a partial mediating role in Grades 5–6. Conclusions The relative contributions of sentence-level comprehension and fluency to deaf students' passage comprehension varied, and sentence-level fluency mediated the relationship between sentence-level comprehension and passage comprehension.

What Does Human Development Index Rating Mean in Terms of Individualism/Collectivism?

2003 ◽  
Vol 8 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Maria José Sotelo ◽  
Luis Gimeno
Keyword(s):  
Human Development ◽  
Human Development Index ◽  
Principal Component ◽  
General Idea ◽  
Development Index ◽  
Low Levels ◽  
The Relationship

The authors explore an alternative way of analyzing the relationship between human development and individualism. The method is based on the first principal component of Hofstede's individualism index in the Human Development Index rating domain. Results suggest that the general idea that greater wealth brings more individualism is only true for countries with high levels of development, while for middle or low levels of development the inverse is true.

Ups and downs on the roller coaster of task conflict: the role of group cognitive complexity, collective emotional intelligence and team creativity

2020 ◽  
Vol 18 (1) ◽  
pp. 23-37
Author(s):  
Andreea Gheorghe ◽  
Oana Fodor ◽  
Anișoara Pavelea
Keyword(s):  
Emotional Intelligence ◽  
Cognitive Complexity ◽  
Empirical Support ◽  
Task Conflict ◽  
Team Creativity ◽  
Mediating Role ◽  
Low Levels ◽  
Explanatory Mechanism ◽  
The Relationship

This study explores the association between task conflict and team creativity and the role of group cognitive complexity (GCC) as a potential explanatory mechanism in a sample of 159 students organized in 49 groups. Moreover, we analyzed the moderating effect of collective emotional intelligence (CEI)in the relationship between task conflict and GCC.As hypothesized, we found that task conflict has a nonlinear relationship with GCC, but contrary to our expectations, it follows a U-shaped association, not an inversed U-shape. In addition,the moderating role of CEI was significant only at low levels. Contrary to our expectation, the mediating role of GCC did not receive empirical support. Theoretical and practical contributions are discussed.

Illicit Economies and Political Violence in Central Asia

2020 ◽  
Author(s):  
Lawrence P. Markowitz ◽  
Mariya Y. Omelicheva
Keyword(s):  
Central Asia ◽  
Political Violence ◽  
Drug Trade ◽  
Weak States ◽  
Collaborative Relationships ◽  
Organized Violence ◽  
Muslim Majority ◽  
Low Levels ◽  
The Relationship ◽  
Terrorist Violence

This chapter examines low levels of terrorist violence in Muslim-majority societies. Studies of terrorism have tended to view the relationship between religion and violence through the narrow lens of security, thereby overpredicting the extent of terrorist violence across societies. After reviewing the various explanations for terrorist violence, and applying them to Central Asia, this chapter explores the conditions under which a state’s involvement in illicit economies—specifically its collusion in the drug trade—can dampen levels of terrorist violence. Combining quantitative analysis (including GIS-enabled tools) with a series of in-depth expert interviews conducted in Central Asia, it emphasizes the complex political economy of security that defines infrastructurally weak states, where political and security apparatuses are often immersed in informal and illicit economies. This approach helps uncover the complex links between religion and organized violence, where state apparatuses are often drawn into collaborative relationships with nonstate actors.

Entrepreneurs and Burnout. How Hardy Pesonality works in this process

2021 ◽  
pp. 003329412199697
Author(s):  
Laura Quiun ◽  
Marta Herrero ◽  
Maria del Carmen Yeo Ayala ◽  
Bernardo Moreno-Jiménez
Keyword(s):  
Emotional Exhaustion ◽  
Descriptive Analysis ◽  
Working Hours ◽  
Burnout Syndrome ◽  
Hierarchical Regression ◽  
Occupational Factors ◽  
Low Levels ◽  
And Performance ◽  
The Impact ◽  
The Relationship

Background Considering the importance of entrepreneurship and the impact of burnout on workers’ health, this study aims to explore the presence of burnout in entrepreneurs and the interaction of hardy personality (HP) in this process. Method The sample included 255 Spanish entrepreneurs. Occupational factors, working hours, labour immersion, HP, burnout syndrome (i.e. Emotional exhaustion, Depersonalization and Lack of accomplishment) and burnout consequences were assessed. Results Descriptive analysis showed that entrepreneurs had low levels of occupational factors, burnout syndrome and consequences. Hierarchical regression exploratory results indicated that working hours, labour immersion, and Emotional exhaustion were the most relevant predictors of the consequences. Besides, mediation models with PROCESS macro (v.3.0) highlighted the indirect effect of occupational factors and showed that emotional exhaustion was the only component of burnout that mediated in between the predictors and the consequences. As well, HP moderated the relationship between occupational factors and emotional exhaustion. Conclusions Occupational factors are the main predictor of burnout in entrepreneurs and HP could prevent their effect on Emotional exhaustion. The results suggest the importance of training to promote HP for better health and performance of entrepreneurs.

When do job insecure employees adapt to change?

2019 ◽  
Vol 25 (3) ◽  
pp. 271-286 ◽  
Author(s):  
Kristi N. Lavigne ◽  
Victoria L. Whitaker ◽  
Dustin K. Jundt ◽  
Mindy K. Shoss
Keyword(s):  
Job Insecurity ◽  
Small Sample ◽  
Adaptive Performance ◽  
Work Behaviors ◽  
Content Type ◽  
Work Tasks ◽  
Main Effect ◽  
Low Levels ◽  
The Impact ◽  
The Relationship

Purpose The purpose of this paper is to examine the relationship between job insecurity and adaptive performance (AP), contingent on changes to core work tasks, which we position as a situational cue to employees regarding important work behaviors. Design/methodology/approach Employees and their supervisors were invited to participate in the study. Supervisors were asked to provide ratings of employees’ AP and changes to core tasks; employees reported on job insecurity. Findings As predicted, changes to core tasks moderated the relationship between job insecurity and AP. Job insecurity was negatively related to AP for those experiencing low levels of change, but was not related to AP for those experiencing high levels of change. Counter to expectations, no main effect of job insecurity was found. Research limitations/implications This study employed a fairly small sample of workers from two organizations, which could limit generalizability. Practical implications The study identifies changes to core tasks as a boundary condition for the job insecurity–AP relationship. Findings suggest that organizations may not observe deleterious consequences of job insecurity on AP when changes to core tasks are high. Originality/value Few researchers have examined boundary conditions of the impact of job insecurity on AP. Furthermore, inconsistent findings regarding the link between job insecurity and AP have emerged. This study fills the gap and expands upon previous research by examining changes to core tasks as a condition under which job insecurity does not pose an issue for AP.

In vitro studies of DNA damage and repair in spermatogenic cells from rats and humans

1998 ◽  
Vol 95 ◽  
pp. 213
Author(s):  
C. Bjørge ◽  
A.-K. Olsen ◽  
R. Wiger ◽  
G. Brunborg ◽  
K. Haug ◽  
...  
Keyword(s):  
Dna Damage ◽  
In Vitro Studies ◽  
Spermatogenic Cells ◽  
Dna Damage And Repair

Cold tolerance of the Antarctic springtail Gomphiocephalus hodgsoni (Collembola, Hypogastruridae)

2001 ◽  
Vol 13 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Brent J. Sinclair ◽  
Heidi Sjursen
Keyword(s):  
Cold Tolerance ◽  
Thermal Environment ◽  
Strong Relationship ◽  
Dry Weight ◽  
Glycerol Content ◽  
Recrystallization Inhibition ◽  
Low Levels ◽  
Inhibition Studies ◽  
The Antarctic ◽  
The Relationship

Cold tolerance of the springtail Gomphiocephalus hodgsoni Carpenter (Collembola: Hypogastruridae) was studied at Cape Bird, Ross Island, Antarctica (77°13′S, 166°26′E). Microclimate temperatures indicate a highly seasonal thermal environment, with winter minima <–39°C. Snow cover significantly buffers both minimum temperatures and cooling rates. Gomphiocephalus hodgsoni survives low temperatures by avoiding freezing. Mean low group supercooling points (SCPs) ranged from –35.4°C in October to –28.3°C in January. The lowest SCP measured was –38.0°C. The high SCP group was very small, making up only 18% of the population in January. In October, G. hodgsoni had a very high glycerol content (>80 μg mg−1 dry weight), although this declined rapidly to low levels (c. 7–10 μg mg−1 dry weight) in January. Quantities of glucose and trehalose were low during October, but steadily increased throughout the summer. Haemolymph osmolality was exceptionally high (up to 1755 mOsm kg−1) at the end of November, but this rapidly declined to c. 500 mOsm kg−1 by late December. The presence of thermal hystersis proteins was indicated by both osmometry on haemolymph samples and recrystallization inhibition studies of springtail homogenates. There was a strong relationship between glycerol content and SCP, but the relationship between haemolymph osmolality, SCP and carbohydrates is uncertain.

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