Mating Research Articles

(Under)water love-linking mate choice and cognition in fish and frogs.

(Under)water love-linking mate choice and cognition in fish and frogs.

Effect of Ethephon on testicular pathology and apoptosis of spermatogenic cell in offspring male rats

Objective To investigate the effect of Ethephon on the testis pathological structure and apoptosis of spermatogenic cell in offspring male rats. Methods Twenty-four healthy female SD rats of 45 days old were randomly divided into control group, low-dose Ethephon group, medium-dose Ethephon group and high-dose Ethephon group according to body weight.The male rats of the same age were selected to mate with female rats.The rats were fed with Ethephon solution of different concentrations or 9 g/L saline every day, and they were continued to be fed with Ethephon during pregnancy and lactation.At the age of 7 days and 14 days, 10 offspring male rats were randomly selec-ted from each group and were put to death.The testicular tissue was stained with HE, and the morphological changes in the testis were observed with light microscope; the apoptotic cells were labeled with terminal deoxynucleotidyl transfe-rase dUTP nick-end labeling (TUNEL method) and the apoptosis index(AI) of testis spermatogenic cells was detected with fluorescence microscope. Results At the age of 7 days, the testis internal structure of the control group developed well, and the spermatic tubules were neatly and compactly arranged.In the low-dose Ethephon group, the seminiferous tubules of the testis were slightly smaller and the spermatogenic cells were loosely arranged compared with the control group.In the medium-dose Ethephon group, the testis seminiferous tubules were slightly disordered and the cell gap increased.In the high-dose Ethephon group, the testis development was poor, the diameter of seminiferous tubules decreased significantly, and the spermatogenic cells arrangement was in disorder.There was no statistically significant difference in spermatogenic cell AI between the low-dose group [(0.54±0.10)%] and the control group[(0.53±0.09)%] (P>0.05), while the spermatogenic cell AI in the medium-dose Ethephon group [(0.63±0.11)%] and the high-dose Ethephon group [(0.81±0.06)%] were higher than that in the control group, thus there exists a statistically significant difference (all P<0.01). The spermatogenic cell AI in the low-dose Ethephon group [(0.54±0.10)%] was lower than that in the medium-dose Ethephon group [(0.63±0.11)%], and the difference was statistically significant (P<0.05). The spermatogenic cell AI in the medium-dose Ethephon group was higher than that in the high-dose Ethephon group, and the difference was statistically significant (P<0.01). At the age of 14 days, the spermatogenic cells AI in control group, low-dose Ethephon group, medium-dose Ethephon group and high-dose Ethephon group were (0.54±0.08)%, (0.65±0.11)%, (0.77±0.11)%, and (0.88±0.10)% respectively, and the spermatogenic cells AI in all groups increased gradually, in which the differences were statistically significant (all P<0.01). Conclusions Excessive dose of Ethephon can induce pathological changes in testicular tissue and increase the apoptosis of spermatogenic cells, resulting in low fertility of offspring rats. Key words: Ethephon; Testis; Spermatogenic cell; Apoptotic index

Bonobo ‘helicopter’ moms stand guard while their sons mate

Bonobo ‘helicopter’ moms stand guard while their sons mate

Population structure of the faba bean blight pathogen Ascochyta fabae (teleomorph, Didymella fabae) in Tunisia

Ascochyta blight, caused by Ascochyta fabae (teleomorph: Didymella fabae ) has decreased faba bean production in Tunisia and worldwide. The teleomorph has recently been observed in Tunisia, raising new questions of how to control this major disease. Isolates (317) of the pathogen were obtained between 2011 and 2013, from four geographical regions in Tunisia (Beja, Bizerte, Jendouba and Tunis). The 240 isolates obtained in 2012 were compared for mating type frequency and genetic variation by using ten polymorphic SSR markers. Of these isolates, MAT1-2 was more common (2:1) in Tunisia than MAT1-1, but this ratio can change according to population. Low to high genetic variation was detected between locations and among pathogen populations. Beja showed the greatest genotypic richness (R = 0.42), followed by Tunis (R = 0.25), Bizerte (R = 0.13), and Jendouba (R = 0.11). Indices of association ( I A ) and Rd were significantly different from 0 in all the populations, suggesting high multilocus linkage disequilibrium and confirming clonal populations. Population structure of the isolates was inferred using Bayesian analyses, Principal Component Analysis (PCA), and Minimum Spanning Networks, which all revealed that the populations from each location were not distinct. Evaluating changes in seasonal genetic diversity showed low to high variances of F ST values between the two cropping seasons in all regions. However, the PCA analysis failed to separate the A. fabae isolates sampled during the two successive seasons into two groups, indicating that these populations did not constitute distinct genetic groups. These results suggest that gene flow was limited among populations, even those separated by short geographic distances. Future studies should enlarge the number of samples of representative populations, to overcome the limitations of a small sample size and to provide a more accurate assessment of A. fabae population structure.

EFFECT OF PHOTOPERIOD ON THE GROWTH PERFORMANCE AND BEHAVIORAL PATTERN OF ACHATINA ACHATINA SNAIL

The study was conducted to evaluate the effect of photoperiod on the growth performance and behavioral pattern of Achatina achatina. Ninety snails of uniform weights were used for the study which lasted for 56 days. The snails were randomly assigned to three treatments and each treatment was replicated three times with 10 snails per replicate. The snails were exposed to different light duration. Treatment 1 had 12 hours light and 12 hours darkness, Treatment 2 was subjected to 18 hours light and 6 hours darkness, Treatment 3 was subjected to 24 hours light. The data collected was analysed using one-way analysis of variance and Duncan multiple range test for significant mean separation. Data were collected on feed intake, weight gain, time of feeding and reproductive behaviors. The results of the experiment showed that there were no significant differences (P>0.05) in final weight gain, average daily weight gain, total feed intake, average daily feed intake, feed conversion ratio, duration of courtship, duration of feeding and cost of feed per kg weight gain between tre atments. The results also showed that there were significant differences in number of eggs laid and mating duration between treatments. From the result, it was concluded that the best photoperiod for Achatina achatina is 24 hours light as it produced the lowest feed conversion ratio and cost of feed per kg weight gain and that was recommended for effective growth of Achatina achatina.

Day length predicts investment in human immune function: Shorter days yield greater investment

Winter is characterized by stressful conditions which compromise health and render animals more vulnerable to infection and illness than during other times of the year. Organisms are hypothesized to adapt to these seasonal stressors by increasing investment in immune function in response to diminished photoperiod duration. Here, we examined this hypothesis in a sample of healthy human participants. Using several functional immune assays in vitro, as well as by utilizing measures of in vivo proinflammatory cytokine levels, we predicted that shorter day length would be associated with greater investment in immunological function. Results revealed that shorter days predicted significant upregulation of several facets of immune function, including natural killer cell cytotoxicity, peripheral blood mononuclear cell proliferation (in response to, and in the absence of stimulation), and plasma levels of interleukin-6, as well as lower rates of Staphylococcus aureus growth in serum ex vivo. Further, consistent with the hypothesis that these trade-offs would be offset by decreased investment in mating effort, shorter day length also predicted lower levels of total testosterone in men. These results suggest that ambient photoperiod may be a powerful regulator of human immunological activity, providing some of the first evidence of seasonal changes in multiple facets of human immune function.

Influence of body size and familiarity on mating and reproductive parameters in the zig-zag ladybird beetle, Menochilus sexmaculatus (Coleoptera: Coccinellidae)

Body size often indicates an individual’s quality and so mate selection is typically for larger individuals, including in ladybirds (Coccinellidae). Many organisms including ladybirds are also are known to refuse mating attempts with familiar individuals, but whether at the expense of mating with larger individuals is not clear. We assessed the cumulative effect of body size and familiarity on mating and reproductive behaviour in the zig-zag ladybird beetle (Menochilus sexmaculatus (Fabricius, 1781) = Cheilomenes sexmaculata (Fabricius, 1781)). For this study, individuals were separated into small- and large-bodied individuals and allowed to mate in all possible combinations. Furthermore, following the first mating, an immediate second mating was provided to the males, with either a familiar (same as in the first mating) or an unfamiliar (new female with the same mating status) female. Mating and reproductive parameters were recorded. The mating duration was longer with familiar partners than unfamiliar individuals. Mating duration was shorter for the second mating, suggesting that mating and ejaculate transfer are costly, to assure higher reproductive success. In this ladybird beetle, familiarity modified mating duration, whereas fecundity and egg viability were influenced by body size.

Does Body Size Influence Male Care? Investigating an Alternative Reproductive Tactic in Manogea porracea (Araneae: Araneidae), a Spider with Amphisexual Care

The balance between the investment of time and energy by males in searching for new partners and in protecting and/or feeding offspring can influence reproductive strategies. Strong competitors may enhance their mating effort, while weak competitors may compensate their disadvantage in intrasexual competition by investing in the increase of offspring survival. This balance and its implications to male reproductive strategies have been extensively investigated in vertebrate species but remain poorly understood in invertebrates, because paternal care is rare. Manogea porracea is the only described solitary spider in which extended male care occurs in the absence of females (i.e. amphisexual care). Large males usually win disputes and prefer large, more fecund females. Therefore, they may increase their reproductive success by prioritizing the investment in the search for additional partners, while small males may compensate their competitive disadvantage by increasing their own parental efforts. We tested the prediction that lighter males will invest in the care of the offspring more often than heavier ones. However, our results indicate that males care for offspring regardless of their size. We discuss how the benefits of parental care may override the costs of reducing the number of potential mates for M. porracea males and suggest new directions for further studies.

Adaptation by way of compromise

Evolutionary Biology Many plants rely on animal pollinators to spread pollen and increase the genetic diversity of their offspring. However, there are trade-offs, because attracting pollinators may also attract herbivores and deterring predation may diminish floral displays. Ramos and Schiestl studied the interplay between mating system, flowers, and chemical defenses over several generations in Brassica rapa plants (see the Perspective by Agren). Evolution driven by pollination and herbivory can be observed after only eight generations, suggesting that trade-offs have large evolutionary consequences. Science , this issue p. [193][1]; see also p. [122][2] [1]: /lookup/doi/10.1126/science.aav6962 [2]: /lookup/doi/10.1126/science.aax1656

Quantitative impact of mating duration on reproduction and offspring sex ratio of Phytoseiulus persimilis (Acari: Phytoseiidae)

Phytoseiulus persimilis is an important biological control agent, commercially produced worldwide. To increase understandings of its reproduction, herein we provided quantitative descriptions of the inflation and deflation of its spermathecae as a function of time and copulation duration, and the quantitative impact of copulation termination on volume of spermatheca vesicle, fecundity, and offspring sex ratio. After mating started, at least one spermatheca started to inflate immediately, but no egg was produced until spermatheca volume reached 1021 µm3. Beyond this size, cumulative fecundity was linearly correlated with vesicle volume. Producing one egg required 36 µm3 volume increase of the vesicle. Each spermatheca vesicle reached its peak size at the end of mating duration (ca. 2.38 h after mating started), and started to shrink immediately. In 24 h, ca. 71% individuals had one completely shriveled spermatheca, while in 72 h all individuals had at least one shriveled spermatheca. The estimated maximum cumulative fecundity per female after a single mating is (69.4±7.7) eggs. No significant impact of mating termination on offspring sex ratio was observed after mating duration reached 60 min, while higher proportion of male offspring was observed when mating duration is 15 or 30 min. This study is the first step to investigate possible male impact on offspring sex ratio in P. persimilis. Our results suggested the number of sperms received during mating be a restriction factor of P. persimilis offspring sex ratio regulation.

Meta analysis of the effect of continuing nursing intervention on high risk patients with diabetic foot

Objective To evaluate the effect of continuous care on patients with high risk of diabetic foot in China. Methods A random control of continuing care for patients with diabetes foot at high risk before June 2018 was published in the full text of the Chinese VP full text database (VIP), the full text database (CNKI), the Chinese biomedical literature database (CBM), Wan Fang, PubMed, Science Library. The test (randomized clinical trial), by 2 researchers, according to the inclusion and exclusion criteria, the literature quality was evaluated and extracted by the document quality standard of Cochrane cooperation network, and the different subgroups were divided according to the difference of the determination time of each outcome index, and the RevMan5.3 software was used to match the data. The required literature is analyzed by Meta. Results A total of 13 randomized clinical trials were included in the Mate analysis, including 1 450 subjects, 721 in the intervention group and 729 in the control group. The results showed that continuous nursing could effectively reduce the value of fasting blood glucose (combined effect MD=-1.34, 95%CI -1.44--1.24, P < 0.01), and effectively reduce the value of glycosylated hemoglobin (combined effect MD=-0.75, 95%CI -1.24- -0.27, P=0.002), and reduce the diabetic foot in patients with diabetic foot risk(combined effect RR=0.31, 95%CI 0.24-0.40, P<0.01). Continuous care could improve patients′ self-management ability and self-foot nursing ability. Conclusions Continuous care can reduce the fasting blood glucose, glycosylated hemoglobin and the incidence of diabetic foot in high-risk patients with diabetic foot, improve their self-management ability and self-foot nursing ability, which is of great significance to prevent and reduce the occurrence and development of diabetic foot. Key words: Continuous care; Diabetic foot; Intervention study; Meta analysis

Nests and seasonal cycle of neocorynura pubescens in colombia hymenoptera halictidae

In the Dept. de Antioquia, Colombia, Neocorynura pubescens is active throughout the year. Females collect pollen from weedy Compositae. Many nests in the banks of a small ditch were surprisingly similar in number of inhabitants, structure, manner of construction, and re-use to those of the strikingly different looking species, N. fumipennis , in Costa Rica. Mating presumably occurs in the nesting area; a clump of males prepared to pass the night on a perch in that area.

Gender differences in attachment from an evolutionary perspective: what is Good for the goose may not be good for the gander

ABSTRACTHuman gender differences tend to be largest in behaviors of high reproductive relevance, that is, sexual and parenting behavior. Such differences show up best in biologically meaningful configurations of specific behaviors rather than in coarse categories. Paternal involvement is thus expressed in aspects and optima which differ from those of maternal involvement. A case in point is sensitivity in its effect on secure attachment, with paternal behavior to be measured by a yardstick different from maternal behavior. Secure father-child attachment may be fostered by optimal levels of paternal activation/stimulation which are different from maternal optima. Paternal action preferences lead to preferences for rough play, which may be especially relevant to the socialization of male offspring. Moreover, fathers—unlike mothers—may perceive their paternal effort as mating effort. The study of father-child attachment—and especially its differences from mother-child attachment—can benefit from considering evolved sex differences in parental behavior.

Plasticity of Mating Duration in Response to Slightly Biased Operational Sex Ratios in the Water Strider (Aquarius remigis): The Effect of Cohabitation Under Standard Laboratory Conditions

In polygynandrous species, males face the trade-off between the pursuit of increased mating opportunities and securing paternity. Within such systems, males need to accurately assess the social composition of the local environment to maximize fitness. Here, we investigated this capability in the water strider (Aquarius remigis), a semi-aquatic insect known to exhibit a broad spectrum of mating behaviors and inhabit a socially diverse and changing environment. Using a combination of methodological designs to track both within- and between-subject effects, individuals remained in same-sex housing prior to being exposed to slightly biased operational sex ratios (2:1 vs. 1:2) with or without prior cohabitation to determine the effects on mating duration. Results show that males were sensitive to these subtle differences in social conditions, mating for longer periods within male-biased environments, but this was true only under conditions with prior cohabitation. In particular, when individuals could acclimate to the testing environment, mating duration dropped precipitously in female-biased conditions. These findings do not support the view that male water striders have consistent behavioral syndromes, and instead show that individuals are able to differentiate between, and adaptively respond to, small changes in the local sex ratio. In addition to improving our understanding of the plasticity of male mating behavior in this species, this study offers new insights for future laboratory research studying reproductive competition across a diverse range of polygynandrous animals.

No evidence that male sexual experience increases mating success in a coercive mating system

Several studies have shown that sexual experience can alter a male's mating behaviour to increase his future mating success. One explanation is that experienced males are better at courting females and inducing them to mate. Experienced males might also be better at identifying higher quality mates, although fewer studies have tested for this benefit. In both cases, however, these potential benefits of sexual experience might be partially offset by the energetic costs of courting and mating, which tend to reduce a male's subsequent ability to invest in sexually selected traits, and thereby reduce his future attractiveness and mating success (i.e. hasten the onset of reproductive senescence). Here we used the eastern mosquitofish, Gambusia holbrooki, to test whether sexual experience elevates male mating success. We housed recently matured males either with full mating access to females (experienced males) or in the visual and olfactory presence of females with which they could not mate (naive males). We then measured the strength of male mate choice for larger, more fecund, females, male mating behaviour (time spent chasing females and the number of copulation attempts) and insemination success. Experienced and naive males did not differ significantly in their mating behaviour and there was no effect of sexual experience on the likelihood of mating or on the number of sperm inseminated (although experienced males had a tendency to be less successful when performing gonopodial thrusts). Experienced males in two-choice trials were, however, significantly more likely to ‘inspect’ both females and had a significantly stronger preference for larger females. Finally, we measured male immune response and growth to test for any costs of the increased mating effort that is concomitant with greater experience. Experienced males had significantly slower postmaturation growth and a significantly weaker immune response than naive males.

Relevance of prolonged first mating in reproductive bioactivities of Dysdercus koenigii (Fabricius, 1775) (Heteroptera: Pyrrhocoridae)

Abstract Adults of Dysdercus koenigii remain in continuous copula for up to 72h. The adaptive significance of prolonged copulation in the reproductive bioactivities of D. koenigii was investigated by a series of interrupted mating experiments. The adults were allowed to mate for a specified duration, after which mating was forcibly terminated. The study indicated that insemination in the female takes place during the first day of mating. This was reflected by the observation that 24h mated females laid fertile eggs. Prolonged mating modifies the female’s reproductive behaviour. The duration of mating had a profound effect on the onset of oviposition as well as the total number of eggs and egg batches laid by a female during her lifetime. Female fertility was also correlated with the duration of mating. Therefore, a female mated for 24h laid fewer fertile eggs in comparison to females mated for 48h or 72h. Hatching success decreased significantly in the egg batches laid by a female during the latter part of her life. A mated female exhibited rhythmic ovipositional behaviour. Our results indicated that the rhythmicity of the oviposition changed as a consequence of the different duration of mating. For instance, in females mated for 24h, there was a change in the number of eggs laid and in the rhythmicity of ovipositional peaks. Further, the rate of oocyte growth appeared to be enhanced by mating. This was evidenced by the shorter inter-oviposition period in the case of females mated for a longer period. It is suggested that throughout mating, females acquire additional sperm and non-gametic resources, such as male accessory gland secretions, which govern their reproductive behaviour and physiology.

Postweaning Isolation Rearing Alters the Adult Social, Sexual Preference and Mating Behaviors of Male CD-1 Mice.

Objective: No study has comprehensively evaluated the effect of postweaning isolation on the social and sexual behaviors of a certain strain of rodents in ethology. The present study aims to explore how and to what extent isolation rearing after postweaning affects the social and sexual behaviors of male CD-1 mice in adulthood systematically.Methods: Male CD-1 mice were randomly assigned to two groups: isolation reared (IS, one mouse per cage, n = 30) and group housed (GH, five mice per cage, n = 15). The mice underwent isolation rearing from postnatal day 23 to day 93. Then, social affiliation, recognition and memory were measured through selection task experiments. Social interaction under a home cage and novel environment were measured via resident–intruder and social interaction test, respectively. Furthermore, sexual preference, homosexual and heterosexual behaviors were measured.Results: Our study found that postweaning isolation increased the social affiliation for conspecifics (p = 0.001), reduced social recognition (p = 0.042) and impaired social memory. As for social interaction, isolated mice showed a remarkably increased aggression toward the intruder male in a home cage or novelty environment. For instance, isolated mice presented a short attack latency (p < 0.001), high attack frequency (p < 0.001) and long attack duration (p < 0.001). In addition, isolated mice exhibited further social avoidance. Contrastingly, isolated mice displayed a reduced sexual preference for female (IS: 61.47 ± 13.80%, GH: 70.33 ± 10.06%, p = 0.038). As for heterosexual behavior, isolated mice have a short mating duration (p = 0.002), long mounting latency (p = 0.002), and long intromission latency (p = 0.015). However, no association was observed between postweaning isolation and homosexual behavior in male CD-1 mouse.Conclusion: Postweaning isolation increased the social affiliation, impaired the social cognition and considerably increased the aggression in social interaction of adult male CD-1 mice. Postweaning isolation induced a decreased sexual preference for female in adulthood. Postweaning isolation extended the latency to mate, thereby reducing mating behavior. No association was observed between isolation and homosexual behavior.

Male mating and female postmating performances in cotton mealybug (Hemiptera: Pseudococcidae): effects of female density.

For insects, female density is closely related to reproductive output. However, little is known about the effects of female density on male mating and female postmating performances. Here, we explored the effects of female density in cotton mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), an invasive, rapidly spreading pest in Asia damaging multiple crops and horticultural plants. Using USB digital microscopes, we investigated the frequency, duration, and intervals of mating for males that were individually supplied with 1, 5, 10, and 15 females. We also evaluated the reproduction of mated females and the sex ratio of their offspring. As the female density increased, males mated with more females while substantially shortening mating intervals. Mating occurred actively at the densities of 10 and 15 females, where males mated four times on average, and some mated 6–9 times. However, mating duration and the observed reproductive parameters of females (preoviposition period, overall period from formation of ovisacs to female death, fecundity, and offspring sex ratio) did not differ significantly with female density. A weak trade-off existed between males’ mating frequency and longevity, but there was no relationship between females’ fecundity and longevity. In conclusion, despite their short lifespan, P. solenopsis males have a high mating capacity, and their mating frequency and intervals can be significantly affected by female density. In contrast, female density has little influence on females’ postmating performance. Our findings indicate the significance of the reproductive biology and life history strategies for rapid establishment and population development of mealybugs in newly invaded regions.

Life table parameters of Iranian population, Tetranychus kanzawai (Acari: Tetranychidae) fed on soybean leaves

The effects of six ambient temperatures (15, 20, 25, 30, 35 and 37.5ºC) on life table parameters of Tetranychus kanzawai Kishida (Tetranychidae) were studied under laboratory conditions on soybean (Glycine max (L.) Merrill). Total immature developmental time of females at the above-mentioned temperatures was 28.55, 16.34, 9.01, 6.96, 5.56 and 5.65 days, respectively. A linear and two nonlinear models of Lactin and SSI were fitted to developmental rate of immature stages of T. kanzawai to predict the developmental rate as a function of temperature, as well as to estimate the thermal constant (k) and critical temperatures. The estimated k for total immature developmental time of females and males was 134.58 and 126.74 DD, respectively. The estimated Topt and Tmax by Lactin model for overall immature stages were 36.20 and 40.70ºC, respectively. Intrinsic optimum temperature (TФ) and T1 (Topt) by SSI model for total immature stages was estimated to be 23.23 and 35.71ºC, respectively. Also the estimated TL and Th of SSI model for overall immature stage were 09.21 and 38.46ºC, respectively. The longest and shortest adult longevity was observed at 15°C (60.63 days), and 37.5°C (7.34 days), respectively. Mated females laid highest and lowest eggs at 25°C (237.96 eggs) and 37.5°C (30.54 eggs), respectively. The rm values ranged from 0.356 day-1 at 30°C to 0.089 day-1at 15°C. The highest value of R0 was 163.55 offspring female-1 at 25°C. The presented information in this study provided new perspective to better management of T. kanzawai on apple trees in Iran.

Testosterone, cortisol, and status-striving personality features: A review and empirical evaluation of the Dual Hormone hypothesis

Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the regulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorticoids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature—including p-curve analyses of published findings; and, (2) “opening the file drawer” and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between testosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research.