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Abstract: Satellite‐based remote sensing has generally necessitated a trade‐off between spatial resolution and temporal frequency, affecting the capacity to observe fast hydrological processes and rapidly changing land surface conditions. An avenue for overcoming these spatiotemporal restrictions is the concept of using constellations of satellites, as opposed to the mission focus exemplified by the more conventional space‐agency approach to earth observation. Referred to as CubeSats, these platforms offer the potential to provide new insights into a range of earth system variables and processes. Their emergence heralds a paradigm shift from single‐sensor launches to an operational approach that envisions tens to hundreds of small, lightweight, and comparatively inexpensive satellites placed into a range of low earth orbits. Although current systems are largely limited to sensing in the optical portion of the electromagnetic spectrum, we demonstrate the opportunity and potential that CubeSats present the hydrological community via the retrieval of vegetation dynamics and terrestrial evaporation and foreshadow future sensing capabilities. [ABSTRACT FROM AUTHOR]

When Earth observation satellite systems are designed, one typically prefers a sun-synchronous orbit. However, the first generations of cubesats from Planet were deployed out of the International Space Station (ISS) and therefore do not obey such an orbit. Their configuration samples at different local times within the mid-latitudes. Consequently, it is in theory possible to exploit photometric techniques and extract highly detailed topographic information. In this study we demonstrate and explore photometry based on Planet cubesat images for Tyndall glacier at the Southern Patagonian icefield, and Zhadang glacier situated on the Tibetan plateau. [ABSTRACT FROM AUTHOR]

An interview with professor Jose Maria Mascaro, a pioneer in dermatology and venereology is presented. Topics discussed include his most important teachers including professor Xavier Vilanova, Bernard Duperrat, who taught him dermatology, general pathology and dermatopathology, greatest achievement of his professional life and funniest experience of his professional life.

High-resolution mapping of tropical forest carbon stocks can assist forest management and improve implementation of large-scale carbon retention and enhancement programs. Previous high-resolution approaches have relied on field plot and/or light detection and ranging (LiDAR) samples of aboveground carbon density, which are typically upscaled to larger geographic areas using stratification maps. Such efforts often rely on detailed vegetation maps to stratify the region for sampling, but existing tropical forest maps are often too coarse and field plots too sparse for highresolution carbon assessments. We developed a top-down approach for high-resolution carbon mapping in a 16.5 million ha region (> 40%) of the Colombian Amazon - a remote landscape seldom documented. We report on three advances for large-scale carbon mapping: (i) employing a universal approach to airborne LiDAR-calibration with limited field data; (ii) quantifying environmental controls over carbon densities; and (iii) developing stratification- and regression-based approaches for scaling up to regions outside of LiDAR coverage. We found that carbon stocks are predicted by a combination of satellite-derived elevation, fractional canopy cover and terrain ruggedness, allowing upscaling of the LiDAR samples to the full 16.5 million ha region. LiDAR-derived carbon maps have 14% uncertainty at 1 ha resolution, and the regional map based on stratification has 28% uncertainty in any given hectare. High-resolution approaches with quantifiable pixel-scale uncertainties will provide the most confidence for monitoring changes in tropical forest carbon stocks. Improved confidence will allow resource managers and decision makers to more rapidly and effectively implement actions that better conserve and utilize forests in tropical regions. [ABSTRACT FROM AUTHOR]

High-resolution mapping of tropical forest carbon stocks can assist forest management and improve implementation of large-scale carbon retention and enhancement programs. Previous high-resolution approaches have relied on field plot and/or Light Detection and Ranging (LiDAR) samples of aboveground carbon density, which are typically upscaled to larger geographic areas using stratification maps. Such efforts often rely on detailed vegetation maps to stratify the region for sampling, but existing tropical forest maps are often too coarse and field plots too sparse for high resolution carbon assessments. We developed a top-down approach for high-resolution carbon mapping in a 16.5 million ha region (>40 %) of the Colombian Amazon -- a remote landscape seldom documented. We report on three advances for large-scale carbon mapping: (I) employing a universal approach to airborne LiDAR-calibration with limited field data; (ii) quantifying environmental controls over carbon densities; and (iii) developing stratification- and regression-based approaches for scaling up to regions outside of LiDAR coverage. We found that carbon stocks are predicted by a combination of satellite-derived elevation, fractional canopy cover and terrain ruggedness, allowing upscaling of the LiDAR samples to the full 16.5 million ha region. LiDAR-derived carbon mapping samples had 14.6% uncertainty at 1 ha resolution, and regional maps based on stratification and regression approaches had 25.6% and 29.6% uncertainty, respectively, in any given hectare. High-resolution approaches with reported local-scale uncertainties will provide the most confidence for monitoring changes in tropical forest carbon stocks. Improved confidence will allow resource managers and decisionmakers to more rapidly and effectively implement actions that better conserve and utilize forests in tropical regions. [ABSTRACT FROM AUTHOR]

Despite the importance of tropical forests to the global carbon cycle, ecological controls over landscape-level variation in live aboveground carbon density (ACD) in tropical forests are poorly understood. Here, we conducted a spatially comprehensive analysis of ACD variation for a continental tropical forest - Barro Colorado Island, Panama (BCI) - and tested site factors that may control such variation. We mapped ACD over 1256 ha of BCI using airborne Light Detection and Ranging (LiDAR), which was well-correlated with ground-based measurements of ACD in Panamanian forests of various ages (r² = 0.84, RMSE = 17 Mg C ha-1, P < 0.0001). We used multiple regression to examine controls over LiDAR-derived ACD, including slope angle, forest age, bedrock, and soil texture. Collectively, these variables explained 14% of the variation in ACD at 30-m resolution, and explained 33% at 100-m resolution. At all resolutions, slope (linked to underlying bedrock variation) was the strongest driving factor; standing carbon stocks were generally higher on steeper slopes. This result suggests that physiography may be more important in controlling ACD variation in Neotropical forests than currently thought. Although BCI has been largely undisturbed by humans for a century, past land-use over approximately half of the island still influences ACD variation, with younger forests (80-130 years old) averaging ~15% less carbon storage than old-growth forests (>400 years old). If other regions of relatively old tropical secondary forests also store less carbon aboveground than primary forests, the effects on the global carbon cycle could be substantial and difficult to detect with traditional satellite monitoring. [ABSTRACT FROM AUTHOR]

Despite the importance of tropical forests to the global carbon cycle, ecological controls over landscape-level variation in live aboveground carbon density (ACD) in tropical forests are poorly understood. Here, we conducted a spatially comprehensive analysis of ACD variation for a mainland tropical forest - Barro Colorado Island, Panama (BCI) - and tested site factors that may control such variation. We mapped ACD over 98% of BCI (∼1500 ha) using airborne Light Detection and Ranging (LiDAR), which was well-correlated with ground-based measurements of ACD in Panamanian forests of various ages (r2 =0.77, RMSE=29MgCha-1, P < 0.0001). We used multiple regression to examine controls over LiDAR-derived ACD, including slope angle, bedrock, soil texture, and forest age. Collectively, these variables explained 14% of the variation in ACD at 30-m resolution, and explained 33% at 100-m resolution. At all resolutions, slope (linked to underlying bedrock variation) was the strongest driving factor; standing carbon stocks were generally higher on steeper slopes, where erosion rates tend to exceed weathering rates, compared to gentle slopes, where weathering in place produces deep, oxic soils. This result suggests that physiography may be more important in controlling ACD variation in Neotropical forests than currently thought. Although BCI has been largely undisturbed by humans for a century, past land-use over approximately half of the island still influences ACD variation, with younger forests (80-130 years old) averaging ∼15% less carbon storage than old-growth forests (>400 years old). If other regions of relatively old tropical secondary forests also store less carbon aboveground than primary forests, the effects on the global carbon cycle could be substantial and difficult to detect with satellite monitoring. [ABSTRACT FROM AUTHOR]

Background: Hepatoerythropoietic porphyria (HEP) is usually a severe form of cutaneous porphyria, characterized biochemically by an increased urinary excretion of polycarboxylated porphyrins. The disease is the result of a profound deficiency (<10% of normal activity) of uroporphyrinogen decarboxylase (UROD) activity. Hepatoerythropoietic porphyria is inherited as an autosomal recessive trait, whereas familial porphyria cutanea tarda is dominant. At least 30 different mutations of the UROD gene have been identified in patients with HEP and familial porphyria cutanea tarda, with 1 predominant missense mutation (glycine–to–glutamic acid substitution at codon 281) in Spanish patients with HEP. Observation: A 5-year-old patient with first-degree–related parents presented with HEP and mild symptomatology. We found low levels of UROD enzymatic activity and a new homozygous mutation of the UROD gene, a phenylanine-to-leucine substitution at codon 46 (F46L). Both parents were healthy carriers of the mutation. The mother had reduced UROD activity (50% of normal), whereas the father had normal UROD activity. Prokaryotic expression of the F46L mutation using a pGEX vector has been used to confirm the deleterious effect of the mutation. When the mother started a new pregnancy, a prenatal study showed the absence of F46L mutation in the fetus and no accumulation of porphyrins in the amniotic fluid. Conclusions: A new mutation in the UROD gene causes a mild HEP phenotype. A normal UROD enzymatic activity was observed in the father, despite the presence of the heterozygous mutation. To our knowledge, this observation is the first description of a prenatal exclusion of HEP. [ABSTRACT FROM AUTHOR]

Acne is a common condition caused by many factors. The pilosebaceous unit is the focus of skin pathology involved in the development of acne. Androgen, sebum, bacteria, immunology and genetics all play a role in pathogenesis. Additionally, external factors such as diet have been unfairly implicated in acne, while drugs and cosmetics may play a role. Management of this disease depends upon identifying the patient's specific condition and treating with products that affect the underlying factors involved in the development of the disease. (J Dermatol Treat (2000) 11 (Suppl 2): S1-S4). [ABSTRACT FROM AUTHOR]

Patients affected by Waldenström's macroglobulinaemia may rarely present specific cutaneous manifestations. The violaceous plaques or tumours infiltrated by lymphoplasmocytoid cells, and the pink, translucent, shiny papules composed of deposits of hyaline monoclonal IgM possess definite clinico-pathological characteristics that may permit the diagnosis before any other data are available. The immunopathological and ultrastructural features of these lesions are described. [ABSTRACT FROM AUTHOR]

The cutaneous changes of the acute form of graft-vs-host reaction are described in two patients who underwent bone marrow transplantation for treatment of severe aplastic anaemia. One patient went on to develop a chronic reaction of the lichenoid type. Histopathology confirmed the presence of 'satellite cell necrosis' from the acute stage of the disease onwards. Direct immunofluorescence showed deposits of immunoglobulin (IgG, IgM), fibrinogen and complement on the necrotic keratinocytes, whilst the basement membrane was positive for C3. These findings suggest that humoral immunity as well as cellular immunity may play a part in the production of the rash. [ABSTRACT FROM AUTHOR]

Systemic candidiasis in intravenous drug abusers (IVDA) is a new syndrome caused by Candida albicans and characterized by the sequential development of skin, eye, and osteoarticular lesions, which together form a typical clinical picture. We studied 30 patients with suggestive skin lesions: papules, nodules, and pustules in hair-bearing areas, particularly the scalp and beard area, associated with hair invasion by candidal hyphae. Ocular and osteoarticular involvement and presence of candidemia in some of the patients suggested blood borne colonization of C. albicans. The infection has been related to ‘brown’ heroin. The origin of C. albicans and the reasons for its exclusive localization in the skin and these organs are discussed. The characteristic clinical picture is widely different from that of classic disseminated candidiasis in immunodeficient patients. Therapy is also discussed. [ABSTRACT FROM AUTHOR]

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Cocoamidopropylbetaines are surfactants frequently used on cosmetics. We have evaluated the irritant capacity of 3 different qualitities of cocoamidopropylbetaine, using the following method: patch tests have been carried out with 5 different dilutions in 67 patients and the results read at 2 days by noninvasive methods (direct visualization, transepidermal water loss (TFWL), laser Doppler flowmetry (LDF)). The results with the 3 methods were concordant. However, the results with the different concentrations were paradoxical, as irritancy did not increase at higher concentrations.We have tried to explain this by the fact that these substances contain by-products (free amidoamine and sodium monocholoroacetate), the concentrations tested all being above the critical micelle concentration and therefore containing both micelles and monomer. Finally, we believe that noninvasive methods such as TEWL and LDF could be of great use in the evaluation of irritant contact dermatitis. [ABSTRACT FROM AUTHOR]

4 patients with chronic photocontact dermatitis were sensitive to cobalt salts. They presented as cases of contact dermatitis from cement or pig fodder with persistent lesions on exposed areas. Only 2 of them had standard patch test positive reactions to chromate and cobalt, but all showed positive photo-patch tests to cobalt. Photo-oxidation tests proved that cobalt salts are photosensitizing. Exposure to cobalt salts was responsible for the patients' chronic actinic dermatitis. [ABSTRACT FROM AUTHOR]

In contrast to Porphyria cutanea tarda (PCT), which is characterized by constant hepatic involvement, the liver seems to be unaltered in Porphyria variegata (PV). However, the authors have found microscopic alterations in the liver of 2 patients with PV (mild inflammation and fibrosis of the portal tracts and the presence of iron deposits in one of the cases). Although these changes could be attributed to other causes, the hypothesis of possible liver involvement in PV is not excluded. [ABSTRACT FROM AUTHOR]

Ulceration is an indicator of unfavourable prognosis in malignant melanoma (MM). But why do melanomas ulcerate?. Possible causes of ulceration were investigated in a group of 69 ulcerated and 69 non-ulcerated malignant melanomas. A significant correlation(P < 0,001) between ulceration and mitotic index was found. In a group of 69 ulcerated malignant melanomas, 49 had over 7, 15 had 4-6, and only 5 had 0-3 mitotic figures per 10 high-power fields. Among 69 non-ulcerated melanomas, 28 had more than 7, 24 had 4 6, and 17 had 0-3 mitotic figures per 10 high-power fields. This study supports the hypothesis that ulceration of melanomas is usually the result of the destruction of the epidermis by the proliferating neoplastic cells or modification of blood supply due to the expansile activity of the tumor. The relationship between ulceration and mitotic activity helps clarify the prognostic significant of ulceration. [ABSTRACT FROM AUTHOR]

Focuses on the simplified experimental open-heart surgery using dog models in a community hospital. Utilization of plastic bubble oxygenators and with gravity return from the vena cava to the bubbling column of the bag; Attachment of a mechanical respirator to the endotracheal tube when the chest of the animal model was opened; Post-operative complications involved in the surgery.

Presents a letter to the editor about cutaneous cryptococcosis in a patient with AIDS.

The article presents a case study related to myeloma-associated systemic amyloidosis which involves the tongue, heart, gastrointestinal tract, skeletal and smooth muscles, and nerves and skin, whereas in secondary systemic amyloidosis the liver, spleen, kidneys, and adrenal glands are predominantly involved. Amyloidosis develops in only 15% of patients with multiple myeloma. In the case study presented, the purpuric cutaneous lesions and macroglosia were the revealing signs of plasma cell dyscrasia. Macroglosia is present in 12% to 40% of cases and is observed as difuse enlargement of the tongue along with firm consistency and teeth indentation.

In our Department. the incidence of sensitization to cobalt has more than doubled in the last 5 years. 28% of cobalt-sensitive patients showed no other sensitivity. Of isolated cobalt sensitive patients, 68% were housewives. We determined by atomic absorption spectrophotometry with a graphite camera, the cobalt and nickel content of the 30 most popular Spanish domestic detergents and cleaners sold in 1985. 78.6% of them contain considerable amounts of cobalt. [ABSTRACT FROM AUTHOR]

The transfixion technique is a therapeutic method introduced for the treatment of angioma and vascular ectasias. It is based on the introduction of synthetic reabsorbable threads, such as polyglycolic acid. The threads are introduced and interlaced into the angioma mass and provoke a reduction of volume by compression. A 7-year-old boy presented a lesion on the distal third of the right side of the tongue. This lesion was present from childhood and progressively increased in size. The lesion had not been previously treated. A biopsy was made to confirm the clinical diagnosis.

Solitary congenital nodular calcification of the skin is a form of cutaneous calcinosis. it appears as a small, firm nodule on the head and extremities of young infants. The histogenesis of this condition is controversial. We cared for two patients with the nodule on the ear. [ABSTRACT FROM AUTHOR]

The article focuses on a double-blind study of prednicarbate versus fluocortin butyl ester in atopic dermatitis. In this study parallel-group, double-blind trial compared the efficacy and tolerability of topical rednicarbate, ointment, with that of fluocortin butyl ester, ointment. A thin layer of topical prednicarbate or fluocortin butyl ester was applied to the affected area of skin twice daily, without occlusion. Results of the 36 patients receiving prednicarbate and 31 of those receiving fluocortin butyl ester were included in the statistical analysis.

Although there are many publications on cutaneous manifestations in AIDS, including adverse drug reactions, and seborrhoeic dermatitis, tinea faciale and atopic dermatitis (22) are all well described in HIV-positive patients, little has been published on the relationship between AIDS and contact dermatitis. A 47-year-old HIV-positive homosexual male, presented 1 year ago with intense outbreaks of seborrhea dermatitis, which improved with topical corticosteroids and ketoconazole but recurred on increasing medication.

An abstract of the article "The doppler-derived myocardial performance Index is more useful than two-dimensional echocardiography in the assessment of donor heart function prior to transplantation," by R. Bonser and colleagues is presented.

Presents a letter to the editor about topical application of steroids as the probable cause of atrophic tendency of lesions.