High-resolution mapping and dispersion analyses of volcanic ballistics emitted during the 3rd July 2019 paroxysm at Stromboli.

A detailed mapping of volcanic ballistic projectiles emplaced in a defined area, represents the starting point to derive preparatory data in hazard and risk studies of ballistics phenomena. Considering as case study the 3rd July 2019 paroxysmal eruption occurred at Stromboli volcano, we map and analyse at very high spatial resolution (8 cm) the distribution of the ballistic spatter clasts emplaced on the E flank of the volcano. The resulting map identifies and reproduces as geospatial polygon elements 152,228 spatter clasts with areal dimensions from 0.03 to 4.23 m2. Dispersed on 0.407 km2, the spatters cover an area of 29,000 m2 corresponding to an erupted products volume from 2.3 to 7.0 × 103 m3, calculated here for the first time. Spatial analyses indicate that the area mostly affected by the clasts emplacement is between N67.5 and N135 directions, identifying a preferential deposition between N112.50 and N123.75 directions. The clasts size distribution rapidly decreases with the size increase, highlighting a nearly constant ratio small/large clasts regardless the distance from the vent. Finally, additional investigations reveal that clasts dispersion parameters decrease progressively with the distance from the vent only along one direction (N67.5), highlighting how the morphology influences the deposition and remobilisation of mapped ballistics.

The archaeological potential of the northern Luangwa Valley, Zambia: The Luwumbu basin.

The Luangwa Basin, Zambia, which forms part of the Zambezi drainage, is strategically located between the Central African plateau and the East African Rift system. The Luangwa River and major tributaries, such as the Luwumbu River, are perennial water sources supporting essential resources that sustain human communities and a rich and diverse fauna and flora. The archaeological record of Luangwa is relatively unknown, despite early archaeological exploration hinting at its potential. Recent research in the southern Luangwa valley, however, suggests that it preserves a long record of hominin occupation spanning the Early to Late Stone Age. The research described here details fieldwork carried out in northeastern Luangwa, in the Luwumbu Basin, that confirms that a relatively deep package of Quaternary deposits, containing evidence of the Stone Age occupation of the region persists in the upper piedmont zone.

NOVEL PATIENT POSITIONING APPARATUS FOR RETINAL SURGERY IN A CASE OF SEVERE KYPHOSIS.

PURPOSE: To describe a novel patient positioning apparatus for intraocular surgery capable of accommodating patients with thoracic kyphosis. METHODS: Case report. RESULTS: A 60-year-old man presented with a macula-off retinal detachment and severe ankylosing spondylitis. The patient was scheduled for combined pars plana vitrectomy and scleral buckle. Because of the patient's severe kyphosis, a custom-designed positioning apparatus was built. The setup involved a canvas with 10 sewn-on straps and a Skytron operating table with strap inserts. Padding and blankets were also used to secure the patient comfortably in the Trendelenburg position. Surgery was uncomplicated and retinal detachment repair was successfully performed. CONCLUSION: To the authors' knowledge, this is the first report detailing a vest-like support apparatus for patients with thoracic kyphosis used in vitreoretinal surgery. This apparatus can be prepared using any conventional operating table, and it offers an effective approach to intraocular surgery for patients who cannot lie flat.

Influence of maternal physical activity on infant's body composition.

BACKGROUND: Physical activity (PA) during pregnancy might contribute to reduce neonatal adiposity, a predictor of metabolic disturbances. OBJECTIVE: The objective of the study was to evaluate the association between maternal PA intensity and neonatal body composition. METHODS: Maternal PA measured by accelerometry and nutrition were documented during pregnancy, as well as neonatal body composition by dual-energy X-ray absorptiometry following delivery. Associations between PA at 17 and 36 weeks (time spent in moderate PA (MPA), vigorous PA (VPA) status and their interaction) and neonatal body composition were addressed by multivariate regression analyses. RESULTS: From 104 women, 50 (48%) and 16 (18%) performed VPA at 17 and 36 weeks of pregnancy. Performing VPA at either time was associated with a decreased birthweight (BW), while only VPA at 17 weeks decreased neonatal adiposity (fat percentage: -2.3 ± 0.8%, p = 0.003). MPA at 36 weeks was associated with an increased lean mass (2.0 ± 0.8 g per min day-1 , p = 0.012). Significant interactions were found for BW and bone mineral content (BMC). MPA at 17 weeks tended to increase BW, but not BMC, in the no VPA strata. By contrast, high levels of MPA (≥112 min d-1 ) combined with VPA at 17 weeks reduced neonatal BMC and BW compared with no VPA (BMC: -5.4 ± 2.0 g, p = 0.008, BW: -302.8 ± 83.7 g, p = 0.0003). Differences were not significant with low MPA levels. CONCLUSIONS: Exercise intensity modulates neonatal body composition. The long-term significance of a reduced BW, adiposity and BMC with VPA requires further study.

Maternal fitness at the onset of the second trimester of pregnancy: correlates and relationship with infant birth weight.

UNLABELLED: What is already known about this subject A healthy life begins in utero and a healthy pregnancy requires a fit and healthy mother. Physical activity during pregnancy provides a stimulation that is essential for promoting optimal body oxygenation and composition as well as metabolic fitness during pregnancy. Although a higher maternal fitness is expected to provide a beneficial fetal environment, it is still unclear whether physical fitness during pregnancy contributes to perinatal health. What this study adds Participation in sports and exercise previously and at the beginning of pregnancy can benefit maternal health by improving cardiorespiratory fitness during pregnancy, irrespective of maternal body mass index. Maternal strength, an indicator of muscular fitness, is an independent determinant of infant fetal growth and can positively influence birth weight. BACKGROUND: It is still unclear whether maternal physical activity and fitness during pregnancy contributes to perinatal health. OBJECTIVES: The aims of this study were to characterize maternal physical fitness at 16 weeks of pregnancy and to examine its effects on infant birth weight. METHODS: Maternal anthropometry (body mass index [BMI] and skin-folds), physical activity, cardiorespiratory fitness (VO2 peak) and muscular fitness (handgrip strength) were assessed at 16 weeks of gestation in 65 healthy pregnant women. Offspring birth weight was collected from maternal charts after delivery. RESULTS: A higher VO2 peak was associated with physical activity spent at sports and exercise before and in early pregnancy (P = 0.0005). Maternal BMI was negatively associated with cardiorespiratory fitness (P < 0.0001) but positively related to muscular strength (P = 0.0001). Unlike maternal cardiorespiratory fitness, handgrip strength was positively associated with infant birth weight (r = 0.34, P = 0.0068) even after adjustment for confounders (adjusted r = 0.27, P = 0.0480). CONCLUSION: A positive relationship between maternal muscular fitness and infant birth weight highlighted maternal strength in pregnancy as a new determinant of infant birth weight.

Transport systems of Ventricaria ventricosa: asymmetry of the hyper- and hypotonic regulation mechanisms.

Hyper- and hypotonic stresses elicit apparently symmetrical responses in the alga Ventricaria. With hypertonic stress, membrane potential difference (PD) between the vacuole and the external medium becomes more positive, conductance at positive PDs (Gmpos) increases and KCl is actively taken up to increase turgor. With hypotonic stress, the membrane PD becomes more negative, conductance at negative PDs (Gmneg) increases and KCl is lost to decrease turgor. We used inhibitors that affect active transport to determine whether agents that inhibit the K(+) pump and hypertonic regulation also inhibit hypotonic regulatory responses. Cells whose turgor pressure was held low by the pressure probe (turgor-clamped) exhibited the same response as cells challenged by hyperosmotic medium, although the response was maintained longer than in osmotically challenged cells, which regulate turgor. The role of active K(+) transport was confirmed by the effects of decreased light, dichlorophenyldimethyl urea and diethylstilbestrol, which induced a uniformly low conductance (quiet state). Cells clamped to high turgor exhibited the same response as cells challenged by hypo-osmotic medium, but the response was similarly transient, making effects of inhibitors hard to determine. Unlike clamped cells, cells challenged by hypo-osmotic medium responded to inhibitors with rapid, transient, negative-going PDs, with decreased Gmneg and increased Gmpos (linearized I-V), achieving the quiet state as PD recovered. These changes are different from those exerted on the pump state, indicating that different transport systems are responsible for turgor regulation in the two cases.

The role of ultrasound in the management of flexor tendon injuries.

The use of ultrasound scanning to establish tendon pathologies was assessed retrospectively in 17 patients in 18 digits. The ultrasound scan demonstrated four patterns: (1) normal intact tendons in four, (2) ruptured tendons in three, (3) tendons in continuity but attenuated in five and (4) tendons in continuity but thickened with fibrosis and decreased movement representing adhesions in five patients. Surgery was undertaken in only three cases, confirming the ultrasound diagnosis in two. Surgery was offered to all three patients with ruptures but was declined by two. Ultrasound imaging helped to avoid surgery in 14 cases by excluding flexor tendon re-ruptures. This allowed on-going mobilisation, leading to recovery of function.

Electrophysiology of turgor regulation in marine siphonous green algae.

We review electrophysiological measures of turgor regulation in some siphonous green algae, primarily the giant-celled marine algae, Valonia and Ventricaria, with particular comparison to the well studied charophyte algae Chara and Lamprothamnium. The siphonous green algae have a less negative plasma membrane potential, and are unlikely to have a proton-based chemiosmotic transport system, dominated by active electrogenic K(+) uptake. We also make note of the unusual cellular structure of the siphonous green algae. Hypertonic stress, due to increased external osmotic pressure, is accompanied by positive-going potential difference (PD), increase in conductance, and slow turgor regulation. The relationship between these is not yet resolved, but may involve changes in K(+ )conductance (G (K)) or active K(+) transport at both membranes. Hypotonic turgor regulation, in response to decreased external osmotic pressure, is approximately 3 times faster than hypertonic turgor regulation. It is accompanied by a negative-going PD, although conductance also increases. The conductance increase and the magnitude of the PD change are strongly correlated with the magnitude of hypotonic stress.

When is a cell not a cell? A theory relating coenocytic structure to the unusual electrophysiology of Ventricaria ventricosa (Valonia ventricosa).

Ventricaria ventricosa and its relatives have intrigued cell biologists and electrophysiologists for over a hundred years. Historically, electrophysiologists have regarded V. ventricosa as a large single plant cell with unusual characteristics including a small and positive vacuole-to-outside membrane potential difference. However, V. ventricosa has a coenocytic construction, with an alveolate cytoplasm interpenetrated by a complex vacuole containing sulphated polysaccharides. We present a theory relating the coenocytic structure to the unusual electrophysiology of V. ventricosa. The alveolate cytoplasm of V. ventricosa consists of a collective of uninucleate cytoplasmic domains interconnected by fine cytoplasmic strands containing microtubules. The cytoplasm is capable of disassociating into single cytoplasmic domains or aggregations of domains that can regenerate new coenocytes. The cytoplasmic domains are enclosed by outer (apical) and inner (basolateral) faces of a communal membrane with polarised K(+)-transporting functions, stabilised by microtubules and resembling a tissue such as a polarised epithelium. There is evidence for membrane trafficking through endocytosis and exocytosis and so "plasmalemma" and "tonoplast" do not have fixed identities. Intra- and extracellular polysaccharide mucilage has effects on electrophysiology through reducing the activity of water and through ion exchange. The vacuole-to-outside potential difference, at which the cell membrane conductance is maximal, reverses its sign from positive under hypertonic conditions to negative under hypotonic conditions. The marked mirror symmetry of the characteristics of current as a function of voltage and conductance as a function of voltage is interpreted as a feature of the communal membrane with polarised K(+) transport. The complex inhomogeneous structure of the cytoplasm places in doubt previous measurements of cytoplasm-to-outside potential difference.

A prospective randomised clinical trial of the intra-operative use of 5-fluorouracil on the outcome of dupuytren's disease.

5-Fluorouracil reduces proliferation rates of fibroblasts, myofibroblast differentiation and contractility of ocular fibroblasts in vitro. This double-blind randomized clinical trial assesses whether intra-operative topical treatment with 5-fluorouracil reduces the recurrence rate after limited excision of Dupuytren's tissue. Patients with two-digit disease were randomized to having 5-fluorouracil (25mg/ml) treatment for 5 minutes on one digit and placebo on the other. Fifteen patients were enrolled with 18 months follow-up. There were no peri-operative complications. Wound healing was not delayed and there was no deterioration in the flexion deformity of the 5-fluorouracil treated digits. Patients were subsequently assessed by joint angle measurement at 3, 6, 12 and 18 months. There was no significant difference between control and 5-fluorouracil treated digits.

The different characteristics of Dupuytren's disease fibroblasts derived from either nodule or cord: expression of alpha-smooth muscle actin and the response to stimulation by TGF-beta1.

Mechanisms behind the onset and progression of Dupuytren's disease are poorly understood. Both myofibroblasts and transforming growth factor beta 1 (TGF-beta(1)) have been implicated. We studied fibroblast cultures derived from nodules or cords of Dupuytren's contracture tissue to determine the proportion of myofibroblasts present in comparison with flexor retinaculum fibroblast cultures. We identified myofibroblasts by immunohistochemical staining for alpha-SMA. We then investigated the effects of TGF-beta(1) stimulation on these fibroblasts. Basal myofibroblast/fibroblast proportions were 9.7% in nodule cell cultures, 2.7% in cord cell cultures and only 1.3% in flexor retinaculum cell cultures. Nodule and cord myofibroblast proportions increased to 25.4% and 24.2%, respectively, in response to TGF-beta(1) treatment. Flexor retinaculum cell cultures showed no response to TGF-beta(1) stimulation. Fibroblasts cultured from specific regions of Dupuytren's tissue retain myofibroblast features in culture. TGF-beta(1) stimulation causes an increased myofibroblast phenotype to similar levels in both nodule and cord, suggesting that previously quiescent cord fibroblasts can be reactivated to become myofibroblasts by TGF-beta(1). This could be an underlying reason for high recurrence rates seen after surgery or progression following injury.

The transport systems of Ventricaria ventricosa: hypotonic and hypertonic turgor regulation.

The time course of hypertonic and hypotonic turgor regulation was studied in Ventricaria (Valonia) using pressure probe and I/V(current-voltage) analysis. Of 11 cells, 9 exhibited hypertonic turgor regulation, ranging from 100% regulation in 150 min to 14% regulation (14% recovery of the decrease in turgor) in 314 min. Some cells began regulating immediately, others took up to 90 min to begin. The resting PD (potential difference) became more positive in most cells. The I/V characteristics became more nonlinear with high resistance between -150 and -20 mV and negative conductance region near -70 mV. Prolonged (16 sec) voltage clamps to negative levels (-100 to -150 mV) showed progressively more rapid current turn-off, but subsequent I/V characteristics were not affected. Clamping to +150 mV, however, abolished the high conductance between -50 and +100 mV to yield a uniform high resistance I/V characteristic, similar to that in high [K+]o. Decreasing illumination from 2.02 micromol sec(-1) m(-2) to 0.5 micromol sec(-1)1 m(-2) had a similar effect. Two out of a total of three cells exhibited hypotonic turgor regulation. Both cells started regulating within minutes and achieved near 50% regulation within 50 min. The PD became more negative. The I/V curves exhibited high resistance between +50 and +150 mV. The characteristics were similar to those in cells exposed to low [K+]o. Prolonged voltage clamps to both negative and positive levels showed slow current increase. Decreased illumination increased the membrane resistance.

Acetylcholine-activated Cl- channel in the Chara tonoplast.

Acetylcholine has long been suggested to play a role in controlling physiological processes in plants, but no mechanism has been shown for its action. We show here that a chloride channel in the tonoplast (vacuolar membrane) of Chara corallina responds to acetylcholine. The channel has a conductance of 45 pS. The effect of acetylcholine is enhanced by nicotine, with the open probability increasing from 0.05 in the presence of 4 mM acetylcholine to 0.3 in the presence of 4 mM acetylcholine + 6 mM nicotine. Some effects of acetylcholine were seen at concentrations as low as 20 microM, with a maximum effect between 1 and 10 mM. In the intact cell, acetylcholine prolongs the depolarized phase of the action potential. We propose that this acetylcholine-gated channel has evolved separately from the mammalian acetylcholine-gated channel, and suggest that this represents a third form of acetylcholine signal transduction, after the nicotinic and muscarinic pathways in animal systems.

Do plastic surgeons resect basal cell carcinomas too widely? A prospective study comparing surgical and histological margins.

Basal cell carcinoma is a common condition facing the plastic surgeon. When formally excised, a surrounding margin of normal skin is included in an attempt to ensure complete excision. We set out to investigate our excision margins in a prospective study of 100 basal cell carcinomas in 86 patients treated by conventional surgical excision. The edge of each lesion was delineated, an excision margin was drawn, and the closest point was identified and measured. The tumours were excised, and the specimens were examined to determine the closest histological margin. A comparison was made between the marked surgical margins and the margins observed on microscopy. The mean observed surgical margin was 3.0 mm and the mean histological margin was 3.7 mm; 44% of the margins agreed to within 1 mm, 79% to within 2 mm and 92% to within 3 mm. There were four incomplete excisions, all at the lateral margin. There was agreement in the position of the closest margin in 69% of cases. The measured surgical excision margins correlated well with those assessed histologically, as did the position of the closest margin. Given a 3 mm margin, 96% of lesions would have been excised completely. We feel that our current practice represents a satisfactory balance between maintaining a low rate of incomplete excision and minimising the sacrifice of normal skin.

Long-term results of facial rejuvenation by carbon dioxide laser resurfacing using a quantitative method of assessment.

Carbon dioxide laser resurfacing has been widely reported as an effective method for treating facial rhytides. Few published series, however, have assessed the long-term results of this procedure. We prospectively reviewed our long-term results of perioral CO(2) laser resurfacing using an accurate, reproducible and quantitative method of evaluation. Wrinkle depth was measured using a silicone elastomer to provide an exact negative-replica mask of the perioral region. Simple light microscopy was then used to measure the depth of rhytides. This was carried out preoperatively, 6 weeks postoperatively and 2 years postoperatively, and the results were compared for 31 patients. CO(2) laser resurfacing achieved a highly significant mean reduction in wrinkle depth at 6 weeks of 91% (paired t -test:P <0.00001), and this was well maintained at 2 years, when the mean reduction in wrinkle depth was 87% (paired t-test: P<0.00001). During the long follow-up, complications were few, with transient erythema being the most common; there were no cases of scarring. As in other series that have reported longer follow-up, we encountered three cases of minor hypopigmentation. We have used light microscopy on silicone moulds as an accurate method of assessing outcome after laser resurfacing of perioral rhytides. The early highly significant reduction in wrinkle depth was maintained at 2 years with minimal associated short-term or long-term morbidity.

Inhibition of cortisol secretion in dispersed head kidney cells of rainbow trout (Oncorhynchus mykiss) by endosulfan, an organochlorine pesticide.

The effects of endosulfan, an organochlorine pesticide, on cortisol secretion in vitro were investigated in enzymatically dispersed head kidney cells of rainbow trout, Oncorhynchus mykiss. First, the conditions for maximal cortisol secretion were characterized by selecting the optimal concentrations of adrenocorticotropin (ACTH) (1 IU/ml) and N(6), 2'-o-dibutyryladenosine 3':5'-cyclic monophosphate (dbcAMP) (2 mM), incubation temperature (15 degrees ) and time period (60 min for ACTH, 120 min for dbcAMP), number of cells per incubation well (75 x 10(6)/ml), and osmolarity of the medium (270 mosmol/L). Exposure of head kidney cells to endosulfan decreased ACTH- or dbcAMP-stimulated cortisol secretion and cell viability in a concentration-dependent pattern and the doses required to disrupt cortisol secretion were significantly lower than doses lethal to the head kidney cells. The median effective concentration of endosulfan (EC(50), the dose that inhibits cortisol secretion by 50%) was 17.3 microM while the median lethal concentration (LC(50), the dose that kills 50% of the cells) was 308 microM. Our study identified endosulfan as an environmental endocrine disrupting chemical that interferes with the normal secretory function of teleost interrenal steroidogenic cells. Multiple sites may be affected within the steroidogenic cells since dbcAMP could not restore cortisol secretion in endosulfan exposed cells.

[Study of terminally ill patients' needs in an university hospital]. / Etude des besoins des patients en phase avancée d'une maladie évolutive dans un CHU.

Within the framework of a project to create a Mobile Palliative Care Unit, in May 2000 we conducted an evaluation of the needs of patients undergoing palliative care in a university hospital centre. Thanks to the use of a standardised questionnaire, a team of doctors and nurses for each service was able to describe the symptoms, treatments and social and family situations as well as assess the eventual outcome of the patients hospitalised in their service who were in an advanced or terminal phase. In total, the study included 52 cases (5.5% of available beds). 81% of patients reported suffering from physical discomfort and 70% from psychological distress. A specific treatment for the disease in question was maintained in 28% of the cases. In 24% of the cases, the patient had social problems. Among all of the patients, 31% were on the waiting list to be transferred to a different location.