Explanatory factors of the psychomotor development of infants aged 1-24 months in N'Djamena (Chad)

Introduction: Psychomotor development (PMD) reflects the cerebral maturation through sensory, motor and psychological acquisitions of an individual. Its evaluation allows an early diagnosis of delays in order to take care of them. The objective of this study was to determine the profile and explanatory factors of PMD of infants in N'Djamena. Methods: This was a cross-sectional study conducted at the “Notre Dame des Apôtres” Hospital in N'Djamena. It involved 428 infants aged 1 to 24 months received in preventive consultation between October 2017 and June 2018. The Denver II scale was used for the assessment of PMD. Data were analyzed with SPSS 21.0 software. Results: the sex ratio was 1.06. The most represented age group was under 3 months (35.5%). The items of gross motor skills were 95% completed, fine motor skills 93.8%, language 84.6% and sociability 68.8% at the 90th percentile. Development was advanced in 56.8% normal in 32.1% and delayed in 2.1%. Statistically significant differences in PMD were observed according to age group (p= 0.000), vaccination status (p= 0.002), feeding mode (p= 0.000), maternal exchange (p= 0.000) and pregnancy follow-up (p= 0.03). Conclusion: The psychomotor development of N'Djamenese infants is similar to that of other African children, although some variations are noted. It is influenced by certain factors related to the infant and the mother.

A novel intramandibular joint facilitates feeding versatility in the sixbar distichodus

The intramandibular joint (IMJ) is a secondary point of movement between the two major bones of the lower jaw. It has independently evolved in several groups of teleost fishes, each time representing a departure from related species in which the mandible functions as a single structure rotating only at the quadratomandibular joint (QMJ). In this study, we examine kinematic consequences of the IMJ novelty in a freshwater characiform fish, the herbivorous Distichodus sexfasciatus. We combine traditional kinematic approaches with trajectory-based analysis of motion shapes to compare patterns of prey capture movements during substrate biting, the fish's native feeding mode, and suction of prey from the water column. We find that the IMJ enables complex jaw motions and contributes to feeding versatility by allowing the fish to modulate its kinematics in response to different prey and to various scenarios of jaw-substrate interaction. Implications of the IMJ include context-dependent movements of lower versus upper jaws, enhanced lower jaw protrusion, and the ability to maintain contact between the teeth and substrate throughout the jaw closing or biting phase of the motion. The IMJ in D. sexfasciatus appears to be an adaptation for removing attached benthic prey, consistent with its function in other groups that have evolved the joint. This study builds on our understanding of the role of the IMJ during prey capture and provides insights into broader implications of the innovative trait.

STUDY ON PRECISE FEEDING CONTROL OF DAIRY COWS BASED ON WIRELESS COMMUNICATION TECHNOLOGY AND DAIRY COW INFORMATION MANAGEMENT TECHNOLOGY

In order to improve the quality of modern dairy industry, it is an inevitable trend to implement intensive control feeding of dairy cows, which is also the development direction in the future. Different feeding methods have different important effects on the health of dairy cows. For example, calves grow and develop rapidly during lactation, change their physiological structure quickly, have strong plasticity, poor inversion and imperfect digestive function. In the production of dairy farms, the scientific feeding mode of calves indirectly affects the overall benefits of dairy farms. Therefore, aiming at the above problems, this paper studies how to accurately control the quality of dairy cows. A cow precise feeding control system based on wireless communication technology and cow information management technology is studied, which solves the problems of wireless information transmission, automatic and accurate cow identification and dual-mode operation of feeder, and ensures the accurate supply of cow concentrate.

Determination of functional structure of soft-bottom marine macrobenthic communities of the Samsun Shelf Area using biological traits analysis

Biological Traits Analysis (BTA) was used to investigate the functional structure of marine macrobenthic communities along the Samsun Shelf Area (SSA). Benthic samples were collected seasonally from five different locations and at four different depths using a Van Veen grab sampler. Macrofaunal communities distributed in the SSA were assessed using 10 biological traits to identify characteristic traits for each depth and location. It was found that variability of benthic ecosystem functions in the SSA was driven by biological traits such as maximum size, living habit, sediment position, feeding mode and type of reproductive behavior. Bivalves, polychaetes and crustaceans of small to medium size, biodepositing, burying themselves in the sediment (burrowers) and feeding in suspension were relatively more abundant at depths of 0–60 m. However, the biomass of Amphiura, Abra, Papillicardium and some polychaetes characterized by medium to large sizes, diffusive mixing, free living and feeding on deposit and subsurface deposit showed higher values at depths below 60 m. In general, it is concluded that the functional structure of the benthic infauna in the SSA has adapted to physical disturbance, and communities distributed in this area consist mainly of taxa resistant to mechanical pressure.

A Novel “回” Pattern Branch Antenna for 3G\4G\WLAN\Bluetooth\Navigation Applications

This study proposes and designs a multiband branch antenna with a structure that imitates the Chinese classical pattern structure. The antenna radiator’s structure is a symmetrical rectangular stub fused with a Chinese classical pattern structure, and the rectangular stub is bent so that the outer and inner stubs are coupled to each other to generate multiple frequency bands. Microstrip line feeding is the feeding mode, and the grounding plate is a trapezoidal structure formed by subtracting two triangles from a rectangle. The overall size of the antenna is 60 × 60 × 1.6 mm3, and the dielectric board adopts FR4. The substrate dielectric constant εr = 4.4, the thickness h = 1.6 mm, and the dielectric loss tangent tanδ = 0.02. For antenna modeling and parameter optimization, HFSS electromagnetic simulation software is used. The antenna can cover 1.49 to 1.60 GHz, 1.87 to 2.51 GHz, and 4.63 to 5.34 GHz and generate three main frequencies: 1.57, 2.15, and 5.06 GHz, according to test result. The antenna has omnidirectional radiation characteristics and can be widely used in future mobile communication network coverage.

Functional Feeding Groups of Macrofauna and Detritus Decomposition along a Gradient of Glacial Meltwater Influence in Tropical High-Andean Streams

Tropical Andean glaciers are retreating rapidly, with possible consequences for trophic structure and ecosystem processes in high Andean meltwater streams. Here, we measured the environmental characteristics, quantified pools of particulate organic matter (POM) and periphyton (Chl. a), sampled benthic macroinvertebrates, determined functional feeding groups (FFG), and performed mesh bag decomposition experiments with Calamagrostis grass detritus at 17 stream sites along a gradient of glacial influence (GI) with 0–23% glacier cover in the catchment at 4050–4200 m a.s.l. in the Andes of Ecuador. POM was unrelated to GI while Chl. a. showed a weak (non-significant) negative relationship to GI. The macrofauna abundance decreased while taxon richness and the number of FFGs per site showed a hump-shaped relationship with increasing GI. Taxa with an opportunistic and generalist feeding mode generally dominated benthic assemblages and were related to high GI levels and low Chl. a. Only shredders were negatively related to GI, but unrelated to POM. Decomposition rates were comparable to those found in temperate alpine streams, and for both fine (0.0010–0.0065; median 0.0028 d−1) and coarse (0.0019–0.0088; median 0.0048 d−1) mesh bags, peaked at intermediate GI values, while the difference between bag types was small and almost constant along the GI gradient. This indicates an overall minor effect of macroinvertebrate shredders compared to that of microbes, in particular at high GI. It also suggests that the relatively high average temperature of these high-altitude equatorial streams (7–10 °C) does not produce higher decomposition rates than those in comparable but colder streams at temperate latitudes. The results suggest that, at the lower end of glacier cover, tropical glacier loss will not change the dominant microbial role in detritus decomposition, but that part of the physical abrasion could be partially replaced by biological shredding.

Effects of polyaluminum chloride (PAX-18) on the relationship between predatory fungi and Lecane rotifers

PAX-18 (polyaluminum chloride) is frequently used in WWTPs (wastewater treatment plants) to overcome sludge bulking. An alternative biological method is the usage of Lecane rotifers, which can be endangered by predacious fungi. We investigated the influence of different PAX-18 concentrations on the relationship between Lecane inermis and predacious fungi (Zoophagus and Lecophagus) differing in feeding mode. High PAX concentration (6 mg Al3+ L−1) strongly limited the number of the rotifers, which in low concentration (1.2 mg Al3+ L−1), after an initial decline, increased, but significantly slower than in control. Under the simultaneous influence of Lecophagus and PAX, rotifers were driven almost extinct at the high concentration, but survived at the lower concentration and increased in the control. When treated with Zoophagus, only one or two rotifers survived in treatments and control. High concentrations of PAX significantly restricted the growth of fungi, whereas in low concentrations and control conditions, their length increased, with Zoophagus growing much quicker than Lecophagus. Zoophagus was significantly more efficient in trapping rotifers regardless of PAX concentration. The trapping ability of mycelium following extended exposure to PAX was strongly limited at high concentrations, in comparison to control. Conidia of Zoophagus turned out to be considerably more resistant to PAX-18 and starvation than Lecophagus conidia.

Evolution of Thyroid Enhancement of Embryogenesis and Early Survival

Iodine imparts protective antioxidant actions that improve the fitness of invertebrate organisms, and peptides carrying iodine initially appear to have served in a defensive capacity. Tyrosine carries multiple iodines in some echinoderms, and these peptides transferred to progeny serve both protective and signaling purposes. This parental relationship appears to be the most likely evolutionary basis for emergence of the vertebrate thyroid endocrine system, and its critically important development-promoting actions in larval and (later) fetal ontogeny. Thyroxine (T4) and Triiodothyronine (T3) induce settlement and stimulate transitions to alternative feeding modes in some echinoderms. This transgenerational relationship has been conserved and elaborated in vertebrates, including humans, which share common ancestry with echinoderms. Thyroid insufficiency is damaging or can be lethal to larval fishes; egg yolk that is insufficiently primed with maternal thyroid hormones (TH) results in compromised development and high mortality rates at the time of first-feeding. Maternally-derived TH supplied to offspring supports the onset of independent feeding in fishes (eye, mouth, lateral line, swim bladder and intestinal maturation) and survival by comparable developmental mechanisms in placental mammals. Fishes evolved precise control of TH secretion and peripheral processing; early metamorphic and feeding mode actions were joined by controlled thermogenesis in homeotherms.