Does heat tolerance actually predict geographic thermal limits of animal species?

To understand species climatic vulnerability, our measures of their thermal tolerance should predict their geographic thermal limits. Yet, this assumption is mostly ungranted. We tested if animals heat tolerance restrict the warmest temperatures they can live at (Tmax), distinguishing among species differently challenged by their thermal environment. For that, we compiled 2350 measurements of species heat tolerance indexes and corresponding Tmax, measured at different microhabitats. We show that reptiles, a flagship for climatic vulnerability studies, are particularly unbounded by their heat tolerance. Contrarily, tolerance restricted marine fish ranges in a non-linear fashion which contrasts with terrestrial taxa. Behavioral tolerance indexes, widely used to predict vulnerability, predicted Tmax inconsistently across Tmax indexes, or were inversely related to it. Heat tolerance restricts geographic limits more strongly for more thermally challenged species. In turn, factors uncoupling heat tolerance and Tmax (plasticity, thermoregulation, adaptation) should be more important for less thermally challenged species at their warm edges of distribution.

Profiling the Effects of Repetitive Morphine Administration on Motor Behavior in Rats

Efficient repetitive clinical use of morphine is limited by its numerous side effects, whereas analgesic tolerance necessitates subsequent increases in morphine dose to achieve adequate levels of analgesia. While many studies focused on analgesic tolerance, the effect of morphine dosing on non-analgesic effects has been overlooked. This study aimed to characterize morphine-induced behavior and the development and progression of morphine-induced behavioral tolerance. Adult male Sprague–Dawley rats were repetitively treated with subcutaneous morphine for 14 days in two dose groups (A: 5 mg/kg/day (b.i.d.) → 10 mg/kg/day; B: 10 mg/kg/day (b.i.d.) → 20 mg/kg/day). Motor behavior was assessed daily (distance traveled, speed, moving time, rearing, rotation) in an open-field arena, before and 30 min post-injections. Antinociception was measured using tail-flick and hot-plate assays. All measured parameters were highly suppressed in both dosing groups on the first treatment day, followed by a gradual manifestation of behavioral tolerance as the treatment progressed. Animals in the high-dose group showed increased locomotor activity after 10 days of morphine treatment. This excitatory phase converted to an inhibition of behavior when a higher morphine dose was introduced. We suggest that the excitatory locomotor effects of repetitive high-dose morphine exposure represent a signature of its behavioral and antinociceptive tolerance.

Values Congruence and Organizational Commitment in Churches: When Do Shared Values Matter?

Leaders and attenders of many churches may feel a tension between contemporary values of Western culture and more conservative values that have traditionally been held by many churches. Discrepancies in values may cause some people to leave their churches. This paper examines the relationship between values congruence (between church attenders and their churches) and organizational commitment, specifically, affective organizational commitment which measures one’s emotional attachment to an organization (i.e., their church). In this study, church attenders (N = 252) provided information about themselves (concerning their personal values, their affective organizational commitment to their church, and demographics) and information about their churches (concerning the church’s values and size). The values measured included both behavioral (tolerance of homosexuality) and cognitive (agreement with evangelical doctrine) aspects. The results indicate that affective organizational commitment to one’s church is positively correlated with values congruence; no evidence was found that affective organizational commitment was correlated to the other variables measured. Further exploratory analyses indicated that this relationship between values congruence and affective organizational commitment varied with both the values of the church and the size of the church. In more conservative churches and in smaller churches, values congruence was more strongly related to affective organizational commitment than in more liberal church-es and larger churches.

Values Congruence and Organizational Commitment in Churches: When Do Shared Values Matter?

Leaders and attenders of many churches may feel a tension between contemporary values of Western culture and more conservative values that have traditionally been held by many churches. Discrepancies in values may cause some people to leave their churches. This paper examines the relationship between values congruence (between church attenders and their churches) and organizational commitment, specifically, affective organizational commitment which measures one’s emotional attachment to an organization (i.e., their church). In this study, church attenders (N = 252) provided information about themselves (concerning their personal values, their affective organizational commitment to their church, and demographics) and information about their churches (concerning the church’s values and size). The values measured included both behavioral (tolerance of homosexuality) and cognitive (agreement with evangelical doctrine) aspects. The results indicate that affective organizational commitment to one’s church is positively correlated with values congruence; no evidence was found that affective organizational commitment was correlated to the other variables measured. Further exploratory analyses indicated that this relationship between values congruence and affective organizational commitment varied with both the values of the church and the size of the church. In more conservative churches and in smaller churches, values congruence was more strongly related to affective organizational commitment than in more liberal churches and larger churches.

Behavioral and neuronal recording of the nucleus accumbens in adolescent rats following acute and repetitive exposure to methylphenidate

The nucleus accumbens (NAc) has been shown to play a key role in the brain's response to methylphenidate (MPD). The present study focuses on neuronal recording from this structure. The study postulates that repetitive exposure to the same dose of MPD will elicit in some rats behavioral sensitization and in others tolerance. Furthermore, the study postulates that NAc neuronal activity recorded from animals expressing behavioral tolerance after repetitive MPD exposure will be significantly different from NAc neuronal activity recorded from animals expressing behavioral sensitization after repetitive MPD exposure at doses of 0.6, 2.5, 5.0, and 10.0 mg/kg. To test this, behavioral and neuronal activity was recorded concomitantly from the NAc of freely behaving adolescent rats (postnatal day 40) before and after acute and repetitive administration of four different MPD doses. Comparing the acute MPD effect to the repetitive MPD effect revealed that the acute response to MPD exhibited dose-response characteristics: an increase in behavioral activity correlated with increasing MPD doses. On the other hand, following repetitive MPD exposure, some animals exhibited attenuated behavior (tolerance), while others exhibited further increases in the recorded behavior (sensitization). Moreover, the neuronal activity following repetitive MPD exposure recorded in animals exhibiting behavioral sensitization was significantly different from neuronal activity recorded in animals exhibiting behavioral tolerance. This implies that when studying the effects of repetitive MPD administration on adolescent rats, it is advisable to simultaneously record both neuronal and behavioral activity and to evaluate all data based on the animals' behavioral response to the repetitive MPD exposure.