Sex Differences in Green Ash

1979 ◽  
Vol 3 (4) ◽  
pp. 173-174
Author(s):  
John T. Talbert ◽  
Robert D. Heeren

Abstract A disproportionately large number of first-generation selections from natural stands of green ash (Fraxinus pennsylvanica Marsh.) have been male. A study was undertaken to determine if male and female green ash differed in several important economic characteristics. Only straightness differences could be shown to be statistically significant, and, even for this trait, several opinions were needed to detect male superiority. Sufficient variation should exist in natural stands to allow inclusion of superior individuals of both sexes in a tree-improvement program.

1989 ◽  
Vol 67 (7) ◽  
pp. 1966-1978 ◽  
Author(s):  
W. R. Remphrey

From initiation to fruit set, which occurs over three growing seasons, eight stages are recognized in the development of axillary inflorescences in the dioecious species Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern, (green ash). In the first season, buds are initiated in the axils of foliage leaves. As the shoots expand in the following spring, the buds complete their development. Although similar at first, differences begin to emerge between vegetative and inflorescence buds in that the latter produce robust second-order meristems, the incipient paracladia, protruding close to the original apex. After about 3–4 weeks, when the initiation of such buds is complete, the terminal and subtending lateral meristems present on each axis develop into a three-membered cluster of floral buds. There was a mean of 214.3 ± 12.2 floral buds initiated per female inflorescence, and the number generally increased with the length of the associated shoot. A ridge, the incipient perianth, begins to form around the periphery of each rounded floral apex. Male and female floral buds are not distinguishable at this stage, but the inflorescence buds are distinctly different from vegetative buds. The male and female buds then diverge in their development in that an identation forms at the summit of the incipient gynoecium and male buds initiate two or three anthers. By autumn, the gynoecium is distinctly conical, with an orifice at its summit, and the anthers are lobed. There is lobing of the perianth ridge, but in the mature flower distinct organs traceable to such lobes could not readily be identified.


1990 ◽  
Vol 68 (9) ◽  
pp. 2035-2043 ◽  
Author(s):  
Campbell G. Davidson ◽  
William R. Remphrey

Architectural variables from male and female green ash (Fraxinus pennsylvanica var. subintergerrima (Vahl) Fern.) comprising three different crown-shape classes were analyzed at four different crown levels to determine which variables influenced crown shape. The narrow conical shape class had the largest mid shoot diameters and the smallest shoot tip abortion frequencies. The broad to round shape class had greater abortion frequency overall. In addition, there was less difference in shoot length between the top and bottom of the crown. The more oval shape class was intermediate for both shoot diameters and abortion frequency. Parent and daughter shoot lengths were longer, midshoot diameters larger, and elevation angles greater with increasing sampling height in the tree. Male trees had shorter shoot lengths and shorter and fewer daughter lateral shoots than female trees. Principal component analysis was used to identify shoot lengths, elevation angles, and abortion frequencies as potentially key variables in understanding crown shape in green ash. Interrelationships of many of the architectural variables suggest that a significant change in one may lead to changes in others, which ultimately would lead to changes in overall crown shape.


1983 ◽  
Author(s):  
Hans Nienstaedt ◽  
Hyun Kang

2021 ◽  
pp. svn-2020-000834
Author(s):  
Koteswara Rao Nalamolu ◽  
Bharath Chelluboina ◽  
Casimir A Fornal ◽  
Siva Reddy Challa ◽  
David M Pinson ◽  
...  

Background and purposeThe therapeutic potential of different stem cells for ischaemic stroke treatment is intriguing and somewhat controversial. Recent results from our laboratory have demonstrated the potential benefits of human umbilical cord blood-derived mesenchymal stem cells (MSC) in a rodent stroke model. We hypothesised that MSC treatment would effectively promote the recovery of sensory and motor function in both males and females, despite any apparent sex differences in post stroke brain injury.MethodsTransient focal cerebral ischaemia was induced in adult Sprague-Dawley rats by occlusion of the middle cerebral artery. Following the procedure, male and female rats of the untreated group were euthanised 1 day after reperfusion and their brains were used to estimate the resulting infarct volume and tissue swelling. Additional groups of stroke-induced male and female rats were treated with MSC or vehicle and were subsequently subjected to a battery of standard neurological/neurobehavioral tests (Modified Neurological Severity Score assessment, adhesive tape removal, beam walk and rotarod). The tests were administered at regular intervals (at days 1, 3, 5, 7 and 14) after reperfusion to determine the time course of neurological and functional recovery after stroke.ResultsThe infarct volume and extent of swelling of the ischaemic brain were similar in males and females. Despite similar pathological stroke lesions, the clinical manifestations of stroke were more pronounced in males than females, as indicated by the neurological scores and other tests. MSC treatment significantly improved the recovery of sensory and motor function in both sexes, and it demonstrated efficacy in both moderate stroke (females) and severe stroke (males).ConclusionsDespite sex differences in the severity of post stroke outcomes, MSC treatment promoted the recovery of sensory and motor function in male and female rats, suggesting that it may be a promising treatment for stroke.


2021 ◽  
pp. 153537022110196
Author(s):  
Nathalie Fuentes ◽  
Miguel Silva Rodriguez ◽  
Patricia Silveyra

Lung cancer represents the world’s leading cause of cancer deaths. Sex differences in the incidence and mortality rates for various types of lung cancers have been identified, but the biological and endocrine mechanisms implicated in these disparities have not yet been determined. While some cancers such as lung adenocarcinoma are more commonly found among women than men, others like squamous cell carcinoma display the opposite pattern or show no sex differences. Associations of tobacco product use rates, susceptibility to carcinogens, occupational exposures, and indoor and outdoor air pollution have also been linked to differential rates of lung cancer occurrence and mortality between sexes. While roles for sex hormones in other types of cancers affecting women or men have been identified and described, little is known about the influence of sex hormones in lung cancer. One potential mechanism identified to date is the synergism between estrogen and some tobacco compounds, and oncogene mutations, in inducing the expression of metabolic enzymes, leading to enhanced formation of reactive oxygen species and DNA adducts, and subsequent lung carcinogenesis. In this review, we present the literature available regarding sex differences in cancer rates, associations of male and female sex hormones with lung cancer, the influence of exogenous hormone therapy in women, and potential mechanisms mediated by male and female sex hormone receptors in lung carcinogenesis. The influence of biological sex on lung disease has recently been established, thus new research incorporating this variable will shed light on the mechanisms behind the observed disparities in lung cancer rates, and potentially lead to the development of new therapeutics to treat this devastating disease.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Song ◽  
Fang Yuan ◽  
Xiaohong Li ◽  
Xipeng Ma ◽  
Xinmin Yin ◽  
...  

Abstract Background Inadequate copper intake and increased fructose consumption represent two important nutritional problems in the USA. Dietary copper-fructose interactions alter gut microbial activity and contribute to the development of nonalcoholic fatty liver disease (NAFLD). The aim of this study is to determine whether dietary copper-fructose interactions alter gut microbial activity in a sex-differential manner and whether sex differences in gut microbial activity are associated with sex differences in hepatic steatosis. Methods Male and female weanling Sprague-Dawley (SD) rats were fed ad libitum with an AIN-93G purified rodent diet with defined copper content for 8 weeks. The copper content is 6 mg/kg and 1.5 mg/kg in adequate copper diet (CuA) and marginal copper diet (CuM), respectively. Animals had free access to either deionized water or deionized water containing 10% fructose (F) (w/v) as the only drink during the experiment. Body weight, calorie intake, plasma alanine aminotransferase, aspartate aminotransferase, and liver histology as well as liver triglyceride were evaluated. Fecal microbial contents were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Fecal and cecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Results Male and female rats exhibit similar trends of changes in the body weight gain and calorie intake in response to dietary copper and fructose, with a generally higher level in male rats. Several female rats in the CuAF group developed mild steatosis, while no obvious steatosis was observed in male rats fed with CuAF or CuMF diets. Fecal 16S rRNA sequencing analysis revealed distinct alterations of the gut microbiome in male and female rats. Linear discriminant analysis (LDA) effect size (LEfSe) identified sex-specific abundant taxa in different groups. Further, total SCFAs, as well as, butyrate were decreased in a more pronounced manner in female CuMF rats than in male rats. Of note, the decreased SCFAs are concomitant with the reduced SCFA producers, but not correlated to hepatic steatosis. Conclusions Our data demonstrated sex differences in the alterations of gut microbial abundance, activities, and hepatic steatosis in response to dietary copper-fructose interaction in rats. The correlation between sex differences in metabolic phenotypes and alterations of gut microbial activities remains elusive.


2019 ◽  
Vol 22 (11) ◽  
pp. 710-723 ◽  
Author(s):  
Atul P Daiwile ◽  
Subramaniam Jayanthi ◽  
Bruce Ladenheim ◽  
Michael T McCoy ◽  
Christie Brannock ◽  
...  

Abstract Background Methamphetamine (METH) use disorder is prevalent worldwide. There are reports of sex differences in quantities of drug used and relapses to drug use among individuals with METH use disorder. However, the molecular neurobiology of these potential sex differences remains unknown. Methods We trained rats to self-administer METH (0. 1 mg/kg/infusion, i.v.) on an fixed-ratio-1 schedule for 20 days using two 3-hour daily METH sessions separated by 30-minute breaks. At the end of self-administration training, rats underwent tests of cue-induced METH seeking on withdrawal days 3 and 30. Twenty-four hours later, nucleus accumbens was dissected and then used to measure neuropeptide mRNA levels. Results Behavioral results show that male rats increased the number of METH infusions earlier during self-administration training and took more METH than females. Both male and female rats could be further divided into 2 phenotypes labeled high and low takers based on the degree of escalation that they exhibited during the course of the METH self-administration experiment. Both males and females exhibited incubation of METH seeking after 30 days of forced withdrawal. Females had higher basal mRNA levels of dynorphin and hypocretin/orexin receptors than males, whereas males expressed higher vasopressin mRNA levels than females under saline and METH conditions. Unexpectedly, only males showed increased expression of nucleus accumbens dynorphin after METH self-administration. Moreover, there were significant correlations between nucleus accumbens Hcrtr1, Hcrtr2, Crhr2, and Avpr1b mRNA levels and cue-induced METH seeking only in female rats. Conclusion Our results identify some behavioral and molecular differences between male and female rats that had self-administered METH. Sexual dimorphism in responses to METH exposure should be considered when developing potential therapeutic agents against METH use disorder.


1987 ◽  
Vol 60 (3) ◽  
pp. 875-883
Author(s):  
Nancy Lipsitt ◽  
Rose R. Olver

The relative contribution of sex and situation has become a contested issue in the understanding of sex differences in behavior. In the present study, 20 male and 20 female undergraduates were asked to describe their behavior and thoughts in six everyday college situations. Three of the situations were constructed to be typically male and three typically female in content. The results indicate that men and women demonstrate sex-specific characteristics in their responses regardless of the type of situation presented. Men exhibited concern with separateness from others, while women exhibited concern with sustaining connection to others, even when faced with situations described to present demand properties that might be expected specifically to elicit the concern characteristic of the other sex. However, for these students the situation also made a difference: female-defined situations elicited the most masculine responses for both male and female subjects.


2004 ◽  
Vol 95 (2) ◽  
pp. 589-592 ◽  
Author(s):  
Anne E. Lincoln

Research has indicated significant age differences between male and female Academy Award nominees and winners. However, this discrepancy may be associated with sex differences in actors' ages when they first begin their acting careers. The present research uses event history analysis to investigate the duration of Academy Award nominees' careers from career start (first film) to first three Academy Award nominations. Analysis suggested controlling for an actor's age at first film explains the sex-age disparity between Academy Award nominees and winners.


1969 ◽  
Vol 115 (3) ◽  
pp. 489-493
Author(s):  
D A Lewis

1. After the administration of large doses of androsterone, epiandrosterone, dehydroepiandrosterone and testosterone to mice, females excreted more of the dose conjugated with sulphuric acid than did males. 2. Liver slices from female mice conjugated androgens with sulphuric acid to a greater extent than did slices from males. 3. Sulphotransferase preparations from livers of female rats and mice catalysed the formation of dehydroepiandrosterone sulphate at a faster rate than preparations from livers of the male animals. 4. A possible explanation for the observed sex differences is discussed.


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