Infantile Phase Research Articles

Current status and challenges of robotic surgery in Pakistan.

Current status and challenges of robotic surgery in Pakistan.

Factors Associated with the Incidence of Atopic Dermatitis in School-Age Children in the Working Area of the Waai Health Center in 2022

Background: Atopic dermatitis is a global health issue if it is seen from the increasing prevalence and high cost of treating atopic dermatitis. Atopic dermatitis is an inflammation of the skin in the form of chronic residive dermatitis, accompanied by itching, and affecting certain body parts, especially in the face in infants (infantile phase) and sural parts of the extremities (in the child phase). Several triggering factors for atopic dermatitis include intrinsic factors such as genetics, characteristics of atopic skin, immunological disorders, stress, and extrinsic factors such as the environment, irritants, allergens, food, microorganisms, and weather.
 Objectives: The purpose of this study was to determine the relationship between genetics, food allergies, and the environment with the incidence of atopic dermatitis in the working area of ​​the Waai Health Center.
 Methods: The research design used was descriptive-analytical with a cross-sectional study approach. The population is all Elementary School 163 Central Maluku, Elementary School 224 Central Maluku, and Elementary School 25 Central Maluku which are in the working area of ​​the Waai Health Center, there are 433 children. Sampling with accidental sampling technique. The sample in this study found 208 children.
 Results: The results obtained a significant relationship between genetics, food allergies, and environment with the incidence of atopic dermatitis with a value (p = 0.000).
 Conclusion: It is recommended for families to supervise and supervise children if there is a history of atopy in family members to reduce the risk factors for atopic dermatitis in children because this atopic dermatitis cannot be cured but its recurrence can be controlled.

Nutritional management of the infant with chronic kidney disease stages 2–5 and on dialysis

The nutritional management of children with chronic kidney disease (CKD) is of prime importance in meeting the challenge of maintaining normal growth and development in this population. The objective of this review is to integrate the Pediatric Renal Nutrition Taskforce clinical practice recommendations for children with CKD stages 2–5 and on dialysis, as they relate to the infant from full term birth up to 1 year of age, for healthcare professionals, including dietitians, physicians, and nurses. It addresses nutritional assessment, energy and protein requirements, delivery of the nutritional prescription, and necessary dietary modifications in the case of abnormal serum levels of calcium, phosphate, and potassium. We focus on the particular nutritional needs of infants with CKD for whom dietary recommendations for energy and protein, based on body weight, are higher compared with children over 1 year of age in order to support both linear and brain growth, which are normally maximal in the first 6 months of life. Attention to nutrition during infancy is important given that growth is predominantly nutrition dependent in the infantile phase and the growth of infants is acutely impaired by disruption to their nutritional intake, particularly during the first 6 months. Inadequate nutritional intake can result in the failure to achieve full adult height potential and an increased risk for abnormal neurodevelopment. We strongly suggest that physicians work closely with pediatric renal dietitians to ensure that the infant with CKD receives the best possible nutritional management to optimize their growth and development.

INZ-701 Prevents Ectopic Tissue Calcification and Restores Bone Architecture and Growth in ENPP1-Deficient Mice.

Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) is the major enzyme that cleaves extracellular adenosine triphosphate (ATP) to generate pyrophosphate (PPi), an inorganic metabolite with potent anticalcification activity. Loss-of-function mutations cause hypopyrophosphatemia and lead to a state of ENPP1 deficiency, which has an acute infantile phase known as generalized arterial calcification of infancy (GACI) and a pediatric to adult phase known as autosomal-recessive hypophosphatemic rickets type 2 (ARHR2). ENPP1 deficiency manifests as ectopic calcification of multiple tissues, neointimal proliferation, premature mortality, impaired growth, and bone deformities. INZ-701, a human ENPP1-Fc protein, is in clinical development as an enzyme replacement therapy for the treatment of ENPP1 deficiency. The pharmacokinetic and pharmacodynamic profile and therapeutic effect of INZ-701 were investigated in Enpp1asj/asj mice, a murine model of ENPP1 deficiency. Enpp1asj/asj mice have undetectable plasma PPi, lower plasma phosphate, and higher FGF23 levels compared with wild-type (WT) mice. Enpp1asj/asj mice on the acceleration diet, containing high phosphate and low magnesium, quickly develop clinical signs, including dehydration, rough hair coat, pinned ears, stiffed legs, and hunched back. Enpp1asj/asj mice treated with vehicle had aforementioned clinical signs plus severe ectopic calcification in multiple tissues and bone defects, characteristics of the clinical phenotype observed in GACI and ARHR2 patients. Our results showed a durable PPi response for more than 3 days after a single dose of INZ-701. Treatment of ENPP1-deficient mice every other day with INZ-701 for 8 weeks restored circulating levels of PPi, prevented pathological calcification in all the tested organs, restored growth parameters, corrected bone defects, improved clinical signs, and decreased mortality in Enpp1asj/asj mice, demonstrating the potential of INZ-701 to treat ENPP1 deficiency. © 2021 American Society for Bone and Mineral Research (ASBMR).

Systematic mapping of developmental milestones in wild chimpanzees

Postnatal development is protracted relative to lifespan in many primates, including modern humans (Homo sapiens), facilitating the acquisition of key motor, communication and social skills that can maximize fitness later in life. Nevertheless, it remains unclear what evolutionary drivers led to extended immature periods. While the developmental milestone literature is well established in humans, insight we can gain from one-species models is limited. By comparing the timing of relatable developmental milestones in a closely related species, the chimpanzee (Pan troglodytes), we can gain further understanding of the evolution of such an extended developmental phase. To date, few studies have specifically attempted to estimate developmental milestones in a manner comparable to the human literature, and existing studies lack sufficient sample sizes to estimate which milestones are more plastic with higher inter-individual variation in the timing of their emergence. Here, we describe the emergence of gross motor, fine motor, social interaction and communication traits from a longitudinal sample of 19 wild chimpanzee infants (8 females and 11 males), Taï National Park, Côte d'Ivoire. Gross motor traits emerged at a mean of 4months, communication traits at 12months, social interaction traits at 14months and fine motor traits at 15months, with later emerging milestones demonstrating greater inter-individual variation in the timing of the emergence. This pattern of milestone emergence is broadly comparable to observations in humans, suggesting selection for a prolonged infantile phase and that sustained skills development has a deep evolutionary history, with implications for theories on primate brain development.

THE DIAGNOSTICS AND CORRECTION OF THE MENTAL STATES OF THE SERVICEMAN, WHO ARE EXPERIENCING PHANTOM PAINS

The article investigates the peculiarities of the mental states of military servicemen, participants of hostilities who are experiencing phantom pain. The consequences of being a soldier in combat conditions were described. The problems faced by the soldiers upon their return from the military zone were identified.Two groups of subjects were formed. The first group included patients who were injured during an anti-terrorist operation, but did not have any limb amputations. The second group comprised those patients, who were injured and experienced traumatic limb amputations. It was found out that the mental state of a serviceman who has experienced a traumatic limb amputation coincides with a state of acute grief. The fact of amputation is perceived as a grievous personal tragedy that has enormous destructive influence. Amputation leads to the collapse of all life prospects and plans of the serviceman, that is manifested in the reassessment of one's "I", a significant reduction in the level of harassment, the need to find a social niche and often in the loss of the life meaning.The characteristic features of the condition of the injured in both groups are high rates of reactive anxiety. Typical mechanisms of psychological protection aimed at eliminating anxiety were defined. The main options of psychological protection of the injured servicemen are aggression, rationalization, regression in the infantile phase with the inherent impunitive response.Key areas of psychotherapy, concerning the work with military personnel were outlined, examples of the methods of mirror therapy, used to overcome phantom pain, were given. The effectiveness of mirror therapy for an amputee soldier was proved through the visual feedback.

Discussion

Discussion

Basketball side cut and jumping shot biomechanical analysis as ACL injury screening

To better understand early brain development, accurate segmentation of infant brain MR images into regions of interest, such as white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF), is one of the most important steps. In the first postnatal year, brain development can be divided into three distinct phases due to myelination and maturation process, i.e., infantile phase (≤ 5 months), isointense phase (6–8 months), and early adult-like phase (≥ 9 months). Among these three phases, the isointense phase exhibits extremely low tissue contrast in both T1-weighted and T2-weighted images, making tissue segmentation extremely challenging. To address this issue, inspired by prior domain knowledge, we developed an anatomy-guided joint tissue segmentation and topological correction framework for 6-month infant brain segmentation, which was implemented with random forest and deep neural network technologies. Experiments showed the advantages of the proposed framework and also demonstrated that anatomical guidance is a key direction to explore for 6-month infant brain segmentation. Our method is available in iBEAT V2.0 Cloud (http://www.ibeat.cloud).

Clinical features and outcome of 6 new patients carrying de novo KCNB1 gene mutations.

Objective:To describe electroclinical features and outcome of 6 patients harboring KCNB1 mutations.Methods:Clinical, EEG, neuropsychological, and brain MRI data analysis. Targeted next-generation sequencing of a 95 epilepsy gene panel.Results:The mean age at seizure onset was 11 months. The mean follow-up of 11.3 years documented that 4 patients following an infantile phase of frequent seizures became seizure free; the mean age at seizure offset was 4.25 years. Epilepsy phenotypes comprised West syndrome in 2 patients, infantile-onset unspecified generalized epilepsy, myoclonic and photosensitive eyelid myoclonia epilepsy resembling Jeavons syndrome, Lennox-Gastaut syndrome, and focal epilepsy with prolonged occipital or clonic seizures in each and every one. Five patients had developmental delay prior to seizure onset evolving into severe intellectual disability with absent speech and autistic traits in one and stereotypic hand movements with impulse control disorder in another. The patient with Jeavons syndrome evolved into moderate intellectual disability. Mutations were de novo, 4 missense and 2 nonsense, 5 were novel, and 1 resulted from somatic mosaicism.Conclusions:KCNB1-related manifestations include a spectrum of infantile-onset generalized or focal seizures whose combination leads to early infantile epileptic encephalopathy including West, Lennox-Gastaut, and Jeavons syndromes. Long-term follow-up highlights that following a stormy phase, seizures subside or cease and treatment may be eased or withdrawn. Cognitive and motor functions are almost always delayed prior to seizure onset and evolve into severe, persistent impairment. Thus, KCNB1 mutations are associated with diffuse brain dysfunction combining seizures, motor, and cognitive impairment.

AN ADAPTABLE SECURE SMART CARD ARCHITECTURE FOR INTERNET OF THINGS AND CLOUD COMPUTING

Internet of Things (IoT) and Cloud Computing paradigm is a next wave in the era of computing and it has been identified as one of the emerging technologies in the field of Computer Science and Information Technology. It has been understood from the literature that integration of IoT and cloud computing is in its infantile phase, that has not been extended to all application domains due to its inadequate security architecture. Hence, in this paper a novel adaptable secure smart card architecture for internet of things and cloud computing is proposed. This is a unique architecture adoptable for the public to have a secure access over diversified smart applications and services distributed in the cloud, anywhere, anytime, any device and any network irrespective of the underlying technologies in a smart environment with one IoT enabled User Adaptable Intelligent Smart Card (UAISC) through mobile devices. The cloud services are integrated and connected through an IP/MPLS (Internet Protocol / Multi-Protocol Label Switching) core System. Elliptic Curve Cryptography (ECC) is used to ensure complete protection against the security risks such as confidentiality, integrity, privacy and unique authentication. This model eliminates ambiguity, ensures security with enhanced performance and realizes the vision of “one secure smart card for any applications and transactions”. The performance of the proposed architecture is tested by establishing a test bed in a simulated environment and the results are reported.

Quality of Service Architecture for Internet of Things and Cloud Computing

of Things (IoT) and Cloud Computing paradigm is a next wave in the era of computing and it has been identified as one of the emerging technologies in the field of Computer Science and Information Technology. The complementarity of these two technologies play a major role in accessing any services and applications anywhere, anytime in the smart environment. But from the literature study, it has been understood that the integration of IoT and cloud computing is in its infantile phase and it has not been extended to all application domains due to its inadequate quality of service architecture. Hence, in this paper a novel, quality of service architecture for internet of things and cloud computing is proposed. This architecture facilitates the public to have an easy access over diversified smart applications and services distributed in the cloud with one IoT enabled Intelligent Smart Card (ISC) through mobile devices with assured quality of service. The cloud services are integrated and connected through an Internet Protocol / Multi Protocol Label Switching (IP/MPLS) core System. The QoS requirements are met with differentiated services. The performance of the proposed architecture is tested by establishing a test bed in a simulated environment.

Axial length measurement techniques in pediatric eyes with cataract

Globe axial length (AL) in children is commonly measured using either contact or immersion technique. Office measurement of AL can be difficult in young children and infants and must often be done under anesthesia in an eye that is unable to cooperate with precise fixation and centration. Contact A-scan measurements yield shorter AL, on average, than immersion A-scan measurements in pediatric eyes. This difference is mainly the result of the anterior chamber depth rather than the lens thickness value. During intraocular lens power calculation, if globe axial length is measured by the contact technique, it will result in the use of an average 1-D stronger IOL power than is actually required. This can lead to induced myopia in the postoperative refraction. In our studied patients, there was a significant difference in prediction error between contact A-scan biometry and immersion A-scan biometry. The immersion A-scan technique is recommended for pediatric IOL power calculation. We also provide a review of biometry in pediatric eyes. The overall mean AL of pediatric cataractous eyes is significantly different than the mean AL of non cataractous eyes. More importantly, the standard deviation is higher in eyes with cataract than in those without. Three phases of eye growth in children have been documented: A rapid, postnatal phase from birth to 6months of age, followed by a slower, infantile phase from 6 to 18months of age, and finally a slow, juvenile phase from 18months forward. In our study, girls had shorter ALs than boys and African-American subjects had longer ALs than Caucasians. Eyes with unilateral cataract had shorter ALs than eyes with bilateral cataract during the earlier years, but had longer ALs during later childhood.

Clinical features of atopic dermatitis in a hospital‐based setting in China

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. There have been few detailed reports of the clinical evaluation of Chinese patients with AD. To give a profile of the clinical features of Chinese AD patients in a university hospital setting. A total of 1008 cases met Hanifin and Rajka diagnostic criteria of AD were recruited at Xinhua Hospital, Shanghai Jiaotong University School of Medicine, China. In our survey, 22.7% patients were mild, 66.6% were moderate and 10.7% were severe according to the SCORAD index. Both the frequency and severity of the male patients were slightly higher. The frequency of asthma among the AD patients was 16.7% and it was increased with the age (χ2 = 205.20, P = 0.000). The frequencies of objective minor signs were demonstrated with age-related changes. Besides, three localized variants including eyelid eczema (49.8%), scalp dermatitis (49.7%), infra-auricular and retroauricular fissuring (44.8%) were commonly observed, especially in the infantile phase (P < 0.01). It was showed significant differences in serum total immunoglobulin E (IgE) and eosinophil cationic protein (ECP) levels of different age groups. The positive rate of Phadiatop was raised after 3 years old and that of the common food allergens were decreased after 6 years old. More males than females had ongoing AD in our survey. Most AD debuted in the first year of the cases. High incidence of the three clinical signs: eyelid eczema, scalp dermatitis and infra-auricular and retroauricular fissuring among the patients suggests it can be a potential valuable diagnostic clue to AD.

Anesthetic management in a pediatric patient with infantile phase Prader-Willi Syndrome: A case report.

Prader-Willi syndrome is a genetic disorder characterized by infantile hypotonia, childhood obesity, characteristic facial appearance, mental retardation, hypogonadism and short stature. It is described as a 2-stage disorder with an infantile hypotonic phase, followed by a childhood obese phase. The first phase, during the newborn and infancy period, is characterized by marked hypotonia, poor sucking, swallowing, coughing, crying, and episodes of asphyxia. Since these signs of poor strength cause poor reversal in the postoperative period, muscle relaxants should be used cautiously, especially in patients in the first phase of the syndrome. We experienced the anesthetic management of a 5-month-old female patient with Prader-Willi syndrome under general anesthesia, without muscle relaxant for excision of BCG lymphadenitis and a preauricular mass.

Endocrine correlates of reproductive development in the male tree-shrew ( Tupaia belangeri) and the effects of infantile exposure to exogenous androgens

The developmental life-history of tree-shrews conforms with the general primate pattern. Consequently, elucidation of the tree-shrew’s neuroendocrine reproductive axis could shed light on the mechanisms that underlie human pubertal development. In the present study, we examined plasma gonadotropin concentrations in male tree-shrews from birth to sexual maturity, and related them to changes in the androgenic and gametogenic status of the testis. A hypogonadotropic infantile phase, during which a stable population of primordial cells is established, extended from birth to approximately Day 30. Following a short juvenile phase (Days 30–40), a pubertal phase of accelerated reproductive development was initiated between Days 40–55. At this time, FSH and LH levels rose and testosterone concentrations reached peak levels coincident with the descent of the testes, accelerated growth in the reproductive tract and the onset of spermatogenesis. To test whether this developmental peak in testosterone secretion is an important determinant in the normal onset of puberty, we exposed male tree-shrews prematurely to high circulating androgen levels for various periods and then examined the impact on key components of the developing reproductive axis. The testosterone implants failed to initiate spermatogenesis and the testes remained in an infantile state for the duration of the treatment, whereas implant removal led to the development of full spermatogenic activity. In both normal and experimental situations, low levels of FSH were associated with a lack of spermatogenic activity while the progression of germ cell development was precisely correlated with rising FSH levels. Taken together, these data establish a comprehensive picture of reproductive development in the male tree-shrew, and also provide support for the hypothesis that FSH plays a primary role in the initiation of spermatogenesis.

Revitalizing Oedipus

Three steps are presented to revitalize the concept of the Oedipus complex and to apply this revitalized concept to clinical work. First, a comprehensive child developmental map is constructed of the road from the early infantile genital phase to the achievement of the full Oedipus stage, integrating the diverse components of self, gender, libido, aggression, ego, superego, object relationship and adaptation. Second, specific developmental lines (e.g., separation-individuation) are magnified in a given patient for close examination to explore the relationship to that patient's overall oedipal conflicts. Third, a reciprocal interaction is fostered between the evolving conceptual framework and the emerging clinical data. The paper contains two in-depth case examples to illustrate the clinical application of these ideas.

5. New therapeutic targets in atopic eczema

One of the recent developments is to treat the disease very early in its development, exactly as is being done in asthma. The aim is to evaluate whether it is possible to modify the disease with long-term management. Can flare-ups be prevented? Is it possible to prevent the ‘atopic march’? The typical progress of a patient with atopic dermatitis (AD) was documented by Kissling & Wuthrich (1). They documented the development of eczema in 106 patients from the infantile phase, through childhood and adolescence into adulthood. The majority of patients experienced recurrent cycles of flare-ups, each of which was controlled by steroids. This recurrent cycle of events is distressing to parents who are also concerned about the ‘atopic march’ (2). Atopic eczema is in most cases the first manifestation of atopic disposition; eczema in childhood, compounded by food allergy, leading to asthma and long-term rhinitis. The general approach to treating AD is to treat relapses/flare-ups and when controlled to withdraw active treatment and use emollients (until the next flare-up). A recent trial has investigated whether continued application of a steroid can prevent or delay the cycle of relapses and treatment. Berth-Jones et al. (3) conducted a randomized vehicle (emollient) controlled trial in patients aged 12–65 with moderate to severe disease, to determine whether fluticasone propionate (at two strengths of 0.05% and 0.005%) can prevent relapses. There was a 1-month stabilization phase, followed by maintenance treatment of both ‘healed’ skin and new areas. The primary end point of the study was the time to relapse. A significant (pv0.001) prolongation of remission with application of fluticasone propionate 0.05% was seen. Significant benefit was also seen with fluticasone propionate 0.005%, but the benefit and statistical significance was reduced (p50.01). NEW THERAPEUTIC STATEGIES AND TARGETS

Temporal relationship between the occurrence of fresh noma and the timing of linear growth retardation in Nigerian children

Fresh noma (cancrum oris) occurs predominantly in children <4 years of age. The key risk factors are poverty, malnutrition and infections. Evolution from an intraoral inflammation to a grotesque oro-facial gangrene is very rapid. We assessed potential relationship between the occurrence of fresh noma and linear growth retardation (LGR) which is prevalent in deprived Third World infants/children between ages 3 and 30 months. LGR is attributed to malnutrition and chronic immunostimulation by environmental antigens. Anthropometric evaluation of children (n = 91) with fresh noma, ages 0-8 years, in relation to US National Center for Health Statistics Reference values was carried out. Age-matched noma-free, poor village children (n = 151) from similar communities as noma cases, and elite urban children (n = 132) served as control groups. Heights and weights were measured and the height for age (HAZ), weight for age (WAZ) and weight for height (WHZ) scores calculated as indices of stunting, underweight and wasting respectively. Serum level of interleukin (IL)-18, a multifunctional cytokine, was also measured. In the age groups 0-4 and 4-8 years, the percentages of noma children <-2.0SD were 91% and 67% respectively. The corresponding values for the village children were 37% and 24% and significantly different (P < 0.001) from the noma group. Only 7% of the elite children aged 4-8 years were stunted. Low body weight and wasting were prominent features of village and noma groups, but more marked in the latter. Associated with noma was a profound increase (P < 0.001) in IL-18 in comparison with urban controls, and a 34% non-statistically significant increase relative to the village control group. Among other functions, IL-18 induces several pro-inflammatory cytokines and the matrix metalloproteinases, influences long bone growth, and consequently may be relevant to growth retardation seen in poor village children and noma victims. These results suggest that occurrence of fresh noma was probably programmed very early in life by malnutrition and chronic infections resulting from replacement of breast milk with contaminated, inferior substitutes. Although not investigated, we speculate that children with fresh noma might also be victims of intrauterine growth retardation as noma is most prevalent during the infantile phase of child growth which starts at mid-gestation and tails off at 4 years.

Gonadotropin-releasing hormone receptor gene expression during pubertal development of female rats.

Appropriate expression of the GnRH receptor (GnRH-R) in gonadotrophs is critical for GnRH signaling and hence for gonadotropin secretion and sexual development. In the present work, we have studied the ontogeny of the steady-state GnRH-R mRNA levels in pituitaries of female rats from Day 5 to Day 55, when sexual maturity is attained. Developmental changes of gonadotropin subunit (alpha, FSHbeta, and LHbeta) mRNA levels were also assessed. In addition, the role of the endogenous GnRH on the maturational changes of GnRH-R and gonadotropin subunit gene expression was investigated. Messenger RNA levels were determined by Northern blot analysis of total RNA from anterior pituitaries. Amounts of the most abundant (5.0 kilobase [kb]) GnRH-R mRNA increased slowly from Day 5 through the infantile period, to peak at Day 20 ( approximately 4-fold increase vs. Day 5). Thereafter the levels of the GnRH-R mRNA decline abruptly by Day 25 (75% decrease vs. Day 20) and then fell slightly until Day 35. Parallel changes were observed on the 4.5-kb transcript of the GnRH-R gene. Alpha subunit mRNA was easily detected at Day 5 and its levels increased quickly through the beginning of the infantile period to peak at Day 10 (3.2-fold increase vs. Day 5); then it decreased by 85% at Day 35. FSHbeta and LHbeta mRNA levels rose slowly until Days 15-20, a short time before GnRH-R. Thereafter, the levels of both mRNAs fell until Day 35 (90% decrease vs. Day 15 for FSHbeta and 50% decrease vs. Day 20 for LHbeta). To ascertain whether developmental activation of the GnRH-R and gonadotropin subunit gene expression is GnRH dependent, we have studied the effect of blocking the endogenous GnRH action by treating developing female rats with the specific GnRH antagonist cetrorelix (1.5 mg/kg body weight/wk, s.c.) through the infantile (Days 5-20) and the juvenile period (Days 20-35). Cetrorelix completely blocked the rise of levels of the two most abundant species, 5.0 kb and 4.5 kb, of GnRH-R mRNA during the infantile phase and dropped them to almost undetectable levels during the juvenile prepubertal period. Cetrorelix also abolished the developmental rise of gonadotropin beta subunit mRNAs during the two periods of the study. In contrast, alpha subunit gene expression tended to decrease, but not significantly, with cetrorelix treatment during the two periods. These data demonstrate that sexual maturation of female rats is advanced by an early and strong induction of GnRH-R and gonadotropin subunit gene expression during the infantile period, followed by weaker persistent activation during puberty. Developmental GnRH-R and gonadotropin beta subunit gene expression is almost entirely GnRH dependent, not only in the juvenile prepubertal stage but also during the infantile period.

GROWTH AND REPRODUCTION OF THE SLUG LIMAX VALENTIANUS FIRUSSAC IN EXPERIMENTAL CONDITIONS

Growth and reproduction of batches and isolated Limax valentianus Férussac slugs reared under long-day photoperiods were compared with those reared under short-day photoperiods combined with higher temperatures during the dark period. Weight increase in L. valentianus occurred in three distinct phases: an initial phase of rapid growth (infantile phase), followed by a phase with a smaller increase in weight (juvenile phase) and finally a phase with minimal growth, during which reproduction occurred (adult phase). This phase ended with a weight decrease, due to senescence. Short days associated with an increase in temperature during the night reduced the reproductive rate, but did not affect growth. Long days were favourable for reproduction. Growth rate was fastest in isolated individuals reared under long days and warm nights, while reproduction was greatest in isolated individuals reared under long days and cool nights. Fertility generally decreased with age, but egg production of slug batches evolved through a maximum, occurring before mean life span. High slug density reduced reproductive rate and longevity.