Precocious Puberty: Causes, Consequences, Daily Environmental Factors, and the need for Community/Societal Support

Precocious puberty, otherwise described as a group of medical conditions that cause early puberty onset, such as a pre-adolescent boy presenting with adult pattern of penile and testicular enlargement or a pre-adolescent girl presenting with mature breast development and onset of menses. Although the sexual and physical characteristics for this condition are well-described in medical literature, the causes are very rarely known. Nevertheless, it has substantial impacts on children’s lives. This is a review on sexual development, premature sexual development, the social complications children suffer from due to early onset puberty, and the associations with daily environmental exposures as possible influences for developing precocious puberty.

The Acquisition of Articulatory Timing for Liquids: Evidence From Child and Adult Speech

Purpose Liquids are among the last sounds to be acquired by English-speaking children. The current study considers their acquisition from an articulatory timing perspective by investigating anticipatory posturing for /l/ versus /ɹ/ in child and adult speech. Method In Experiment 1, twelve 5-year-old, twelve 8-year-old, and 11 college-aged speakers produced carrier phrases with penultimate stress on monosyllabic words that had /l/, /ɹ/, or /d/ (control) as singleton onsets and /æ/ or /u/ as the vowel. Short-domain anticipatory effects were acoustically investigated based on schwa formant values extracted from the preceding determiner (= the ) and dynamic formant values across the /ə#LV/ sequence. In Experiment 2, long-domain effects were perceptually indexed using a previously validated forward-gated audiovisual speech prediction task. Results Experiment 1 results indicated that all speakers distinguished /l/ from /ɹ/ along F3. Adults distinguished /l/ from /ɹ/ with a lower F2. Older children produced subtler versions of the adult pattern; their anticipatory posturing was also more influenced by the following vowel. Younger children did not distinguish /l/ from /ɹ/ along F2, but both liquids were distinguished from /d/ in the domains investigated. Experiment 2 results indicated that /ɹ/ was identified earlier than /l/ in gated adult speech; both liquids were identified equally early in 5-year-olds' speech. Conclusions The results are interpreted to suggest a pattern of early tongue–body retraction for liquids in /ə#LV/ sequences in children's speech. More generally, it is suggested that children must learn to inhibit the influence of vowels on liquid articulation to achieve an adultlike contrast between /l/ and /ɹ/ in running speech.

Morphometry and anatomic variations of the posterior cerebral artery in Northeast Brazil

Introduction: The posterior cerebral artery (PCA) is a vessel of the Circle of Willis. Variations are observed in the first segments of the PCA and its branches, especially in the thalamoperforating arteries (TPAs) and in the artery of Percheron (AP). Anatomical presentation of these arteries is of relevant clinical importance for safer neurosurgical approaches. Objective: To identify the most frequent PCA and TPA patterns and the morphometry of P1 and P2 branches in Northeast Brazil. Methods: This is an observational study. Nine Circle of Willis from human brains were isolated. PCA morphology, TPAs classification and prevalence of AP were evaluated. The length and diameter of the P1 and P2 segments of the PCA were measured. Values of p 0.05). Conclusions: Adult pattern of PCA was the most frequent and trifurcation of PCA, a rare anomaly, was found in 22,2% of specimens. TPAs were mostly bilateral multiple type. No differences between sides in the length and diameter of the segments P1 and P2 were found. These data can contribute to safer approaches to neurological pathologies in this population in Northeast Brazil.

Missing Midline Metatarsals Conform to Plantar Arterial Arch Dysgenesis

Midline metatarsal ray deficiencies, which occur in approximately half of congenital short limbs with fibular deficiency, provide the most distal and compelling manifestation of a fluid spectrum of human lower-extremity congenital long bone reductions; this spectrum syndromically affects the long bone triad of the proximal femur, fibula, and midline metatarsals. The bony deficiencies correspond to sites of rapid embryonic arterial transitioning. Long bones first begin to ossify because of vascular invasions of their respective mesenchymal/cartilage anlagen, proceeding in a proximal-to-distal sequence along the forming embryonic limb. A single-axis artery forms initially in the embryonic lower limb by means of vasculogenesis. Additional arteries evolve in overlapping transitional waves, in proximity to the various anlagen, during the sixth and seventh weeks after fertilization. An adult pattern of vessels presents by the eighth week. Arterial alterations, in the form of retained primitive embryonic vessels and/or reduced absent adult vessels, have been observed clinically at the aforementioned locations where skeletal reductions occur. Persistence of primitive vessels in association with the triad of long bone reductions allows a heuristic estimation of the time, place, and nature of such coupled vascular and bony dysgeneses. Arterial dysgenesis is postulated to have occurred when the developing arterial and skeletal structures were concurrently vulnerable to teratogenic insults because of embryonic arterial instability, a risk factor during arterial transition. It is herein hypothesized that flawed arterial transitions subject the prefigured long bone cartilage models of the rapidly growing limb to the risk of teratogenesis at one or more of the then most rapidly growing sites. Midline metatarsal deficiency forms the keystone of this developmental concept of an error of limb development, which occurs as a consequence of failed completion of the medial portion of the plantar arch. Therefore, the historical nomenclature of congenital long bone deficiencies will benefit from modification from a current reliance on empirical physical taxonomies to a developmental foundation.

Acculturation and Physical Activity Among Latinas Enrolled in a 12-Month Walking Intervention

This report evaluates the relationship between acculturation and assimilation with the physical activity (PA) outcomes of a 12-month walking intervention for postpartum Latinas ( n = 81, M age = 29.2 years, M BMI [body mass index] = 30.0). PA was measured by ActiGraph GT1M accelerometers. Acculturation and assimilation were measured by the Hazuda Acculturation and Assimilation Scales. Data were collected at baseline, 6 months, and 12 months. Results showed a trend for participants classified in the least acculturated groups to engage in more moderate-to-vigorous PA than participants classified in the higher acculturated/assimilated groups for two dimensions of acculturation (Adult Proficiency in English Versus Spanish, p = .002; Adult Pattern of English Versus Spanish Language Usage, p = .001) and two dimensions of assimilation (Childhood Interaction With Members of Mainstream Society, p = .028; Adult Functional Integration With Mainstream Society, p ≤ .001). No other significant effects were observed. Findings highlight the continued need to understand the context in which acculturation and assimilation influence PA.

Seed production and growth of Neopomacentrus cyanomos (Bleeker, 1856) in captivity

Development of the regal demoiselle Neopomacentrus cyanomos (Bleeker, 1856) from egg to maturation and spawning stage is described using hatchery reared specimens. Larval rearing of N. cyanomos was carried out using zooplankton as the starting feed up to the 10th day post-hatch (dph). Larval and post-larval growth was studied for a period of 340 dph. Caudal fin rays began to develop from 8th dph and the larval body depth increased considerably from 9th dph onwards. Towards the 10th dph, at about 5.7 mm total length (TL) half of the specimens underwent notochord flexion. Larvae exhibited decreased transparency with increased pigmentation of the pre-anal body, characterised by presence of stellate melanophores. Towards 15th dph, the pectoral, pelvic, dorsal, anal and caudal fins were visible with fin rays. The soft dorsal fin started showing pigmentation from 20th dph onwards and the spinous dorsal from 30th dph onwards. Towards 30th day, black pigments were found distributed all over the body. Pigmentation steadily increased from 30th day onwards and the juveniles fully attained the adult pattern of body colouration by about 90-100 days. First spawning occurred on the 340th dph at a size of 64-73 mm TL.

EphA activation overrides the presynaptic actions of BDNF

The adult pattern of neural connectivity is shaped by repulsive and attractive factors, many of which are modulated by activity. Although much is known about the actions of these factors when studied in isolation, little is known about how they interact. To address this question, we examined the effects of sequential or coapplication of brain-derived neurotrophic factor (BDNF) and Fc-conjugated ephrin-A5 or EphA5 in cultured embryonic hippocampal neurons. BDNF promotes neurite outgrowth and synapse formation, and when applied acutely, it elicits an increase in ongoing synaptic activity. Members of the ephrin family of ligands and receptors can be repulsive and prevent formation of synaptic contacts. Acute exposure to either ephrin-A5-Fc or EphA5-Fc transiently enhanced synaptic activity when applied alone, but when applied prior to BDNF, they dramatically reduced the electrophysiological effects of the neurotrophin. Conversely, BDNF had no effect on subsequently applied ephrin-A5-Fc or EphA5-Fc. Consistent with this, ephrin-A5-Fc also prevented BDNF-induced activation of p42/44 MAPK. The effect of ephrin-A5-Fc appears to be presynaptic, as it prevented the BDNF-induced increase in spontaneous miniature postsynaptic current frequency, whereas EphA5-Fc did not. These results suggest that these factors can be categorized differently, with the contact-mediated activation of EphA receptors by ephrin-A5 overriding the diffusion-mediated effect of BDNF.

Development of excitatory and inhibitory neurotransmitters in transitory cholinergic neurons, starburst amacrine cells, and GABAergic amacrine cells of rabbit retina, with implications for previsual and visual development of retinal ganglion cells

Starburst amacrine cells (SACs), the only acetylcholine (ACh)-releasing amacrine cells (ACs) in adult rabbit retina, contain GABA and are key elements in the retina’s directionally selective (DS) mechanism. Unlike many other GABAergic ACs, they use glutamic acid decarboxlyase (GAD)67, not GAD65, to synthesize GABA. Using immunocytochemistry, we demonstrate the apoptosis at birth (P0) of transitory putative ACs that exhibit immunoreactivity (IR) for the ACh-synthetic enzyme choline acetyltransferase (ChAT), GAD67, and the GABA transporter, GAT1. Only a few intact, displaced ChAT-immunoreactive SAC bodies are detected at P0. At P2, ChAT-IR is detected in the two narrowly stratified substrata of starburst dendrites in the inner plexiform layer (IPL). Quantitative analysis reveals that in the first postnatal week, only a small fraction of SACs cells express ChAT- and GABA-IR. Not until the end of the second week are they expressed in all SACs. At P0, a three-tiered stratification of GABA-IR is present in the IPL, entirely different from the adult pattern of seven substrata, emerging at P3–P4, and optimally visualized at P13. At P0, GAD65 is detectable in normally placed AC bodies. At P1, GAD65-IR appears in dendrites of nonstarburst GABAergic ACs, and by P5 is robust in the adult pattern of four substrata in the IPL. GAD65-IR never co-localizes with ChAT-IR. In a temporal comparison of our data with physiological, pharmacological, and ultrastructural studies, we suggest that transitory ChAT-immunoreactive cells share with SACs production of stage II (nicotinic) waves of previsual synchronous activity in ganglion cells (GCs). Further, we conclude that (1) GAD65-immunoreactive, non-SAC GABAergic ACs are the most likely candidates responsible for the suppression of stage III (muscarinic/AMPA-kainate) waves and (2) DS responses first appear in DS GCs, when about 50% of SACs express ChAT- and GABA-IR, and in 100% of DS GCs, when expression occurs in all SACs.