Precision of mangrove sediment blue carbon estimates and the role of coring and data analysis methods

Carbon accumulation in coastal wetlands is normally assessed by extracting a sediment core and estimating its carbon content and bulk density. Because carbon content and bulk density are functionally related, the latter can be estimated gravimetrically from a section of the core or, alternatively, from the carbon content in the sample using the mixing model equation from soil science. Using sediment samples from La Paz Bay, Mexico, we analyzed the effect that the choice of corer and the method used to estimate bulk density could have on the final estimates of carbon storage in the sediments. We validated the results using a larger dataset of tropical mangroves, and then by Monte Carlo simulation. The choice of corer did not have sizable influence on the final estimates of carbon density. The main factor in selecting a corer is the operational difficulties that each corer may have in different types of sediments. Because of the multiplication of errors in a product of two variables subject to random sampling error, when using gravimetric estimates of bulk density, the dispersion of the data points in the estimation of total carbon density rises rapidly as the amount of carbon in the sediment increases. In contrast, the estimation of total carbon density using only the carbon fraction as a predictor is very precise, especially in sediments rich in organic matter. This method, however, depends critically on the accurate estimation of the two parameters of the mixing model: the bulk density of pure peat and the bulk density of pure mineral sediment. The estimation of carbon densities in peaty sediments can be very imprecise when using gravimetric bulk densities. Estimating carbon density in peaty sediments using only the estimate of organic fraction can be much more precise, provided the model parameters are estimated with accuracy. These results open the door for simplified and precise estimates of carbon dynamics in mangroves and coastal wetlands.

Prioritizing mangrove conservation across Mexico to facilitate 2020 NDC ambition

There is a scale mismatch between mangrove conservation and carbon emission mitigation policies despite mangroves contributing disproportionally to global carbon sequestration. Using Mexico as a case study in the integration of these scales, we estimate mangrove carbon value and deforestation rates at the municipio (local government) scale and develop a prioritization model that indicates where to focus conservation efforts. By using previously published global models of carbon stocks, Mexico-specific carbon sequestration data, and calculating gross deforestation, we found that the current rate of deforestation will result in a social cost of 392.0 (± 7.4) million US$ over the next 25 years. The prioritization model identified 26 municipios of 175, where if all mangroves are conserved, 50% of this cost could be avoided. Bridging the gap between research and governmental action using local initiatives will be paramount for the effective management of mangrove carbon.

In vitro Evaluation of Corrosion and Cytotoxicity of Orthodontic Brackets

The corrosion resistance of AISI 304 stainless steel (AISI 304 SS) and manganese stainless steel (low-nickel SS) brackets in artificial saliva was investigated. The cytotoxic effects of their corrosion products on L929 cell culture were compared by two assays, crystal violet, to evaluate cell viability, and MTT (3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide), for cell metabolism and proliferation. The atomic absorption spectroscopic analysis of the corrosion products demonstrated that nickel and manganese ion concentrations were higher for the AISI 304 SS-bracket immersion solution as compared with the low-nickel SS brackets. Scanning electron microscopy and energy-dispersive spectroscopy demonstrated less corrosion resistance for the AISI 304 SS brackets. Although none of the bracket extracts altered L929 cell viability or morphology, the AISI 304 SS-bracket extracts decreased cellular metabolism slightly. The results indicated that the low-nickel SS presents better in vitro biocompatibility than AISI 304 SS brackets. Abbreviations used: AISI, American Iron and Steel Institute; EDS, energy-dispersive spectroscopy; OD, optical density; ISO, International Organization for Standardization; MTT, (3-{4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; NiSO4, nickel sulfate; SEM, standard error of the mean; WHO, World Health Organization; and TNF, tumor necrosis factor.

Galaxy evolution. Black hole feedback in the luminous quasar PDS 456

The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spherical stream of highly ionized gas in the broadband x-ray spectra of the luminous quasar PDS 456. This persistent wind is expelled at relativistic speeds from the inner accretion disk, and its wide aperture suggests an effective coupling with the ambient gas. The outflow's kinetic power larger than 10(46) ergs per second is enough to provide the feedback required by models of black hole and host galaxy coevolution.

A case-control study of the risk factors for cystic echinococcosis among the children of Rio Negro province, Argentina

In 1984 the prevalence of cystic echinococcosis (CE) in Rio Negro province in central Argentina reached alarming levels, with almost 6% of children aged 7-13 years infected with the causative agent, Echinococcus granulosus. Although the control activities developed between 1980-2000 have now lowered the prevalence of infection in this age-group to 1.1%, transmission of E. granulosus has clearly not ceased. The aim of the present study was to identify possible flaws in the control programme and the risk factors associated with CE. The 24 cases and 66 controls used were identified during a survey of the 1,070 schoolchildren attending 12 schools in Ingeniero Jacobacci, Rio Negro province. In interviews based around a standardized questionnaire, the adult female with responsibility for each subject (usually the mother but sometimes a grandmother or guardian) was asked 70 questions about the child and his or her immediate family, their contact with dogs and relevant environmentmental factors, and their level of contact with the control programme. Univariate and multivariate analyses were used to determine odds ratios (OR) and their 95% confidence intervals (CI). The main risk factors found to be significantly associated with CE were having a family member with the disease (OR = 3.11; CI = 0.92-10.47), spending the first years of life surrounded by a large number of dogs (OR = 2.11; CI = 1.2-3.5), and having a father who slaughtered sheep at his workplace (OR = 1.14; CI = 1.04-1.24). Obtaining drinking water from a tap (OR = 0.28; CI = 0.08-1.01) also remained in the final model, as a protective factor.

Localization, purification and specificity of the full-length membrane-bound form of human recombinant alpha 1,3/4-fucosyltransferase from BHK-21B cells

Fucosyltransferase III [galactoside 3(4)-L-fucosyltransferase; EC 2.4.1.65] (FT3) is a Golgi type II membrane protein that catalyses the synthesis of fucosylated Lewis motifs that are associated with cell-adhesion events and are differentially expressed during cell differentiation. In the present work, the full-length membrane bound form of FT3 has been expressed in baby hamster kidney cells. The enzyme has been found in the trans-Golgi and trans-Golgi network (TGN) of the transfected cells, where it appeared as monomers and dimers, but not as oligomers with high molecular masses. Therefore oligomerization is not the basis for correct localization of FT3 in the Golgi. The enzyme has been purified, with a final yield of 2% and a total purification of 2900-fold, by DEAE-Sepharose, SP-Sepharose, GDP-Fractogel and Superdex 200 chromatography. The purified enzyme showed a clear preference for the Gal beta 3GlcNAc motif in oligosaccharides conjugated with the hydrophobic tail (CH(2))(3)-NHCO-(CH(2))(5)-NH-biotin. Substitution of galactose with alpha 2-linked fucose or alpha 2,3-linked N-acetylneuraminic acid yielded a 1.9-fold increase or a 43% decrease in activity respectively. The enzyme showed no activity towards asialofetuin, a glycoprotein containing the Gal beta 3GlcNAc acceptor motif. Therefore it has been concluded that the membrane-bound form of FT3 is present in the Golgi and the TGN in an equilibrium of monomers<-->dimers, which might fucosylate glycans from glycolipids, but not from glycoproteins.

Ovine Echinococcus granulosus transmission dynamics in the province of Rio Negro, Argentina, 1980-1999

In this work, the impact of a hydatidosis control programme for dogs on the intermediate ovine host was specifically analysed to determine the levels of prevalence achieved and the dynamics of parasite transmission, as well as to evaluate the quality of diagnostic systems in slaughterhouses. A field study was conducted in four slaughterhouses (Valcheta, Los Menucos, Jacobacci, Bariloche) that process animals coming from all the departments within the work area. The control programme for dogs entailed treating dogs with 5 mg/kg praziquantel at 2-month intervals for 20 years. Sample size was determined with a 10% error margin and a 95% significance level. Harvested viscera (liver, lungs, kidneys) were preserved in 5% formaldehyde and sent to the laboratory for diagnostic confirmation of both positive and negative specimens. The 61% initial prevalence dropped to 18.3% at the end of the 10-year period, observed differences proving significant (Chi-square=15.454, P=0.00). There were statistically significant increases in infection prevalence with age (Pearson's Chi-square=133.61, P=0.00). Overall, 37.2% of hydatidosis cases diagnosed in slaughterhouses were considered non-hydatid by histological study. On the other hand, 1.1% of those diagnosed as healthy were found to be infected with hydatidosis. The number of hydatid cysts per animal increased with age: 0.04 in lambs and 1.22 in adults (linear regression equation, -0.0539+0.0127 x age), whereas the average for the whole period was 3.7% in lambs and 20.5% in adults. Viability studies indicated that 63.8% of parasitised animals had viable cysts, out of which 53.3% were fertile. Diagnosis of infection in sheep made by means of an adjusted statistical design and with histological confirmation of the presumptive diagnosis made in slaughterhouses demonstrated the flaws of the official systems for epidemic surveillance of hydatidosis. However, there was no overall significant difference in slaughterhouse and laboratory data.Ro was 0.53 and could imply a decrease in reproductive capacity of the parasite and steady state extinction.

Rate of infection and of reinfection by Echinococcus granulosus in rural dogs of the province of Rio Negro, Argentina

Hydatidosis (cystic echinococcosis) constitutes a serious public health problem in the Province of Rio Negro, Argentina. In the present work it was intended to evaluate the prevalence of the canine echinococcosis in rural areas of the Province of Rio Negro and studied the reinfection rate in dogs after treatment with Praziquantel during the period 1980-1997. A total of 496 dogs were studied in 18 canine concentrations in order to establish the initial prevalence rate which was 42.3%. From 1980 onward dogs should have been systematically treated with anthelmintic every 2 months in rural areas and every 6 months in urban areas. We estimated that approximately 65% of dogs were treated. To determine the reinfection rate, 476 dogs (1984) and 598 dogs (1996) were studied after anthelmintic treatment during two sequential time periods (0-45; 46-90 days). In both cases treated animals were compared with untreated dogs. Prevalences were 3.5%, 6.7% and 21.3% in 1984 and 0.8%, 4.0% and 10.0% in 1996. For the purpose of surveillance a total number of 21,444 dogs were studied during 18 years. Prevalence of Echinococcus granulosus decreased significantly in the first year from 42.3% to 6.1%.

Molecular analysis of three patients with interstitial deletions of chromosome band 14q31

Two patients and one three generation family with interstitial deletions of distal chromosome band 14q31 are described. The deletions were initially identified by chromosome analysis; we have used highly informative simple sequence repeat polymorphisms to define the deletions at the molecular level. This analysis also establishes the parental origin of the deleted chromosome. One of the patients was initially described as having a terminal deletion of chromosome 14 from 14q31 to 14qter; we show here that this child has instead an interstitial deletion of band 14q31. The smallest deletion involves a single anonymous DNA marker and is associated with an almost normal phenotype. The two patients with larger deletions have phenotypes similar to those seen in previously described cases of interstitial deletions of chromosome 14, including minor dysmorphic features and developmental delay. Delineation of these deletions allows the ordering of markers within the 14q31 region, in which the gene for the degenerative neurological disorder Machado-Joseph disease is localised.

[Hydatidosis control in the province of Río Negro, Argentina: evaluation of the veterinary health care activities. 1]

BACKGROUND

Hydatidosis constitutes a serious Public Health problem in the Province of Rio Negro, Argentine. This situation has promoted the implementation of a Control Programme, carried out in 1979. The accumulated experience of 13 years works is presented in this study.

METHODS

The strategy used is that of the Primary Health Care; and community participation is a fundamental component of the programme as well as local planning and the approach of risk in the allocation of resources. The activities included the systematic dogs deparasitation with Praziquantel, carried out by health agents from the system rural hospitals (health promoters not professional staff); the surveillance of dogs rate of infection by means of diagnostic deparasitations made with hydrobromide or arecoline, educational talks at schools, the use of mass media, an the determination of ovine parasitism in studies carried out in the area abattoirs.

RESULTS

The information registered indicates that 1,86,156 dog deparasitations with Praziquantel were carried out with a consumption of 443,533 tablets and 11,178 deparasitations with hydrobromide and Arecoline. A continuous decrease of rates appears during the Period 1979-1992. So, dog Echinococcosis was reduced from 41.5% to 4.24% and ovine Hydatidosis from 61% to 12.7%. Consequently, Human Hydatidosis has decreased from an incidence rate of 64.11 x 100,000 in the age group of 0 to 10 years to and incidence rate of 4.46 x 100,000.

CONCLUSIONS

Finally, the results of the Programme are analyzed in the light of other global experiences of control; and the strategies that should be put into practice in the future with a view to a final limitation of the rate of transmission to man are analyzed.

[Hydatidosis control in the province of Río Negro, Argentina: development of primary care programs]

Hydatidosis is a serious Public Health problem in the Province of Río Negro, Argentina. This situation has promoted the implementation of a control programme based on the canine systematic deparasitation with Praziquantel, health education, work control and care of persons. The accumulated experience of 15 years works, carried out to develop the last work--line mentioned above, is presented in this study. The activities includes the registry of human cases, the early identification of asymptomatic carries, the infected persons derivation to the hospital system in order to allow their appropriate treatment, the longitudinal follow up of the operated cases and the epidemiologic surveillance of the human hydatidosis situation. A network of laboratories was organized, as a support to satisfy the hospital demand, under the coordination of a central laboratory of reference and serologic surveys, among the groups at risk, were also carried out. The information registered indicates that a total of 60,078 serologic tests were carried out in the whole Province: out of them, 22,899 corresponded to hospital demand (DD5) and 37,179 to serologic surveys (originally latex, then DD5, and now Elisa). 65% of the cases, diagnosed by official register, is derived from rural areas to complexity hospitals, to be put under surgical treatment, and, out of these operated persons, only 3.9% is derived from the appearance of clinical symptomatology. A sustained reduction in the average days of stay, in lethality and in the rate of serologic prevalence in school children from 7 to 13 years of age, are achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification and characterization of sporadic and inherited mutations in exon 31 of the neurofibromatosis (NF1) gene

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders in humans, and presents with a variety of clinical symptoms, which are highly variable in expression. The mutation rate for NF1 is high, with as many as half of all cases resulting from new mutations. Although the NF1 gene has been cloned and its cDNA sequence determined, the specific role of the NF1 gene product in contributing to the NF1 mutations is one of the first steps in correlating genotype with clinical symptoms of the disease. In this paper we describe two independent mutations in exon 31 of the NF1 gene identified following polymerase chain reaction (PCR) amplification, heteroduplexing, and single strand conformational polymorphism (SSCP) analysis. One is a novel insertion that segregates with the disease phenotype in that particular family (5852insTT), while the other is a further example of the sporadic, recurrent C-->T mutation previously described in the literature (C5842T). The relationship between these mutations and clinical features of NF1 presented by the patients will be discussed.

[Serologic longitudinal follow-up of surgically treated patients for hydatidosis]

Beginning with the register of human hydatidosis cases, kept by hydatidosis struggle programs of Rio Negro Province, was done the serologic longitudinal follow-up in patients operated on in the period 1980-1987, in the influence area of Ingeniero Jacobacci, Rio Negro, Argentina. The local Supervision Program obtained blood samples of 36 patients during 1990 (59% of them were operated on in the considered period), five patients died corresponding the remaining to persons to whom did not live in Ingeniero Jacobacci or to whom were not possible to evaluate. The blood samples were studied by DD5, confirming the disease immunologically in 18 cases (50%). In this work are evaluated possible causes of reinfection: surgery technic, individual susceptibility, immunological factors.

[Control of hydatidosis in the Province of Rio Negro, Argentina: epidemiology]

In this paper we attempt to present a general view of the situation of hydatidosis in the Province of Rio Negro, Argentina, considering the magnitude of infection in man and dog. Because of its seriousness a 10 year program for the control of hydatidosis has been carried out, which included veterinary and medical care. The number of human cases with hydatidosis in the period 1981-1988 was determined by a retrospective study of the registers of Public Health. From 1188 cases registered in the period, the annual numbers varied between 152 in 1981 and 104 in 1988. This implies an incidence rate of 40 x 100,000. The most frequent localization observed was in the liver. The average days of hospitalization has decreased to 15.8 per patient. Screening seroepidemiological surveys using DD5 allowed us to determine that the prevalence rate was in some departments of 2330 x 100,000. Also included are the results, up to now, of 10 years of field work done in the program area.

Contractures in patients with Williams syndrome

Williams syndrome is a multisystem disorder, including a characteristic facies and habitus. Intellectual, neurologic, and cardiovascular dysfunction occur; vascular disease may be progressive. Joint contractures affected 10 of a group of 20 children and young adults. In 3 of 10 patients, the contractures were severe enough to interfere with daily activities; in 3 the effect was only moderate. The contractures developed in early childhood and usually did not improve or worsen with time. Large and small joints were affected and usually were symmetrical. Their occurrence did not correlate with vascular disease. The contractures could not be attributed to a neurologic cause.

Diamine oxidase content in urine of patients with renal failure

Diamine oxidase activity was determined in twenty-seven samples collected from normal subjects and from patients with renal failure. The enzyme activity was absent or very low in the urine samples of normal subjects. The highest diamine oxidase activity was found in the patients affected with nephrosis, the Fanconi syndrome and renal transplantation, showing a relationship between urinary enzymatic activity and tubular damage, in accordance with the localization in the convoluted tubules.

Skin reactions to bug bites as a result of xenodiagnosis

Cutaneous allergic reactions to bites of two bug species Triatoma infestans and Dipetalogaster maxima, were studied in an area where T. infestans is the local domestic vector. While more delayed skin reactions occurred with the indigenous vector, reactions also occurred with D. maxima. Repeated exposure to D. maxima produced more intense immediate skin reactions. First-stage D. maxima bugs produced a lower frequency and intensity of skin reaction. It is concluded that further work on this problem is necessary as it prejudices the use of xenodiagnosis in field surveys.

Report of large kinship with familial translocation between chromosomes 21 and 22

This paper reports a large kinship with a familial (21;22) translocation occurring in both the balanced and the unbalanced states. Recurrence risks for the (21;22) translocation in the unbalanced state are high (14%) for the offspring of female carriers as compared with those for the offspring of male carriers (4%), but the offspring of male carriers appear to have a much higher risk (50%) of being balanced carriers than those of female carriers (30%).

On the nature of chromophore in pig kidney diamine oxidase

The nature of the 500-nm chromophore in pig kidney diamine oxidase was investigated by absorption spectroscopy and fluorescence in the presence of various chelating or carbonyl-specific reagents. From the spectroscopic measurements the following conclusions can be drawn. First, the 500-nm absorption band is not due to copper, the reduction of which is not related to the disappearance of this band. Second, phenylhydrazine and cycloserine give rise, upon reaction with the enzyme, to absorptions very similar to those of a pyridoxal enzyme, aspartate aminotransferase. Third, these enzyme derivatives are unexpectedly non-fluorescent. Copper removal, obtained after prolonged incubation of cycloserine-treated enzyme in the presence of reducing and chelating agents, leads to a fluorescence similar to that of cycloserine-aspartate transminase. It is proposed that copper is coordinated to the postulated pyridoxal phosphate of diamine oxidase through the pyridine nitrogen.