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1.
Summary The structure and development of the elaborate scale case ofMallomonas adamas (Synurophyceae) was studied throughout the cell cycle. Immediately following division, scale cases normally possess 30 siliceous scales, or 5 rows of 6 scales each. Scale rows overlap one another and spiral around the cell in a clockwise direction when viewed from either end of the cell. Throughout interphase, a duplicate set of 30 scales is manufactured and secreted into the existing scale case in a precise sequence, resulting in a scale case with 60 scales, or 5 rows of 12 scales each. Scales are not added to the scale case in rows, but individually positioned within the cytoplasm and inserted one at a time over the entire surface of the cell. Scales appear to occupy specific positions in the scale case. Scale cases are dynamic cell coverings, their elaborate patterning being maintained throughout cell growth and during division when half the parental scales are inherited by each daughter cell. 相似文献
2.
Predation on vertebrates is infrequent in gibbons. In a 14-month field study of the central Yunnan black crested gibbon (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China, we observed gibbons attacking, killing and eating giant flying squirrels (Petaurista philippensis). During 845 h of observation on one study group, the gibbons attacked giant flying squirrels 11 times, and succeeded in
4 cases. Although all members of the group attempted to attack the squirrels, all four successful attacks were made by the
same adult female. The victims were infants in three cases and a juvenile or sub-adult in one case. Black crested gibbons
also attacked adult giant flying squirrels by grabbing their long tails and throwing them from the canopy, but they failed
to catch or kill the prey in three cases observed. Passive meat sharing occurred in three out of four successful cases. Besides
hunting giant flying squirrels, the black crested gibbons also ate eggs or chicks in two birds’ nests and one lizard. 相似文献
3.
This report describes three cases of infant adoption in red howler monkeys (Alouatta seniculus) of Venezuela. In one case, a lactating female adopted her infant granddaughter after the infant's mother disappeared and
the infant survived for the next 25 months. In the second case, an adult female adopted her infant granddaughter for nine
days while the infant's mother was still a group member. In the third case, a nulliparous female temporarily adopted an infant
from a neighboring group. The details and the possible reasons for these adoption are described. 相似文献
4.
Damaris Selle Francesca Chiesura Lorenzoni Adriano Sernagiotto Gianni D'Ambros Paola Bellencin 《Aerobiologia》1992,8(3):369-377
Summary The town of Belluno has a high number of wild and cultivated plants whose pollen has various degrees of importance from an allergological point of view.In this preliminary study we have taken into consideration the distribution and the flowering period of these species, correlating them with the data on the quantity and type of pollen collected by a sampler placed on the roof of the City Hospital, and also with the results of the allergometric tests (Prick Tests) carried out in the Broncho-Pneumological Department during the first 9 months of 1990.The wild specis of spring-flowering trees which can be found in the woods surrounding the city (Fagaceae, Betulaceae, Corylaceae) and along the gravel banks of the Piave river (Salicaceae) as well as the Graminaceae which are widespread both in the urban area and in the fields outside the city and some cultivated species (Robinia, Tilia, Acer) which flower a little later, are the species which produce most pollen and which are held responsible for allergies. However, only the pollen of the Graminaceae gave rise to cases of mono-sensitivity (16%) (apart from one case of Betulaceae and Corylaceae and one case ofArtemisia as well asDermatophagoides) (9.7%). For the other species, the positive reactions were associated with the positive reactions to the pollen of other species belonging to different families and/or to other factors. 相似文献
5.
Cryptococcal meningitis is an uncommon infection globally, including Nigeria. This systemic fungal infection often is associated with immunodeficiency. The most common causes of meningitis in Nigeria in the 2–3 year age group are the malaria parasites and bacteria. The concomittant infections ofCryptococcal neoformans andPlasmodium falciparum are uncommon. We present here the report of a case of fatal cryptococcal meningitis with malaria infection in a 2 year old child from Nigeria (one of the malaria endemic regions of the world). This case emphasizes the importance of doing a combination of fungal and bacterial cultures as well as looking for malarial parasites in the determination of etiological agents of meningitis in any hospital in Africa. We suggest that cerebrospinal fluid from meningitis cases must be cultured using Sabouraud dextrose agar and any growth on the agar must be examined using Indian ink. 相似文献
6.
A survey of 150 cases with sporotrichosis seen at the Dermatological Clinic of Kurume University Hospital from February 1962 to October 1986 was reported. The proportion of cases with sporotrichosis to the total number of outpatients was 0.17%. Greater percentage of cases fell into the less than 10 years old or more than 40 years old groups. The male to female ratio was 11.46, and 38 cases occurred in farmers. Geographic distribution was remarkable, especially around the Chikugo and Yabe river. Sixty-four cases showed the cutaneous lymphangitic type and 85 cases the localized cutaneous type and one case atypical type. The face and upper extremities were the most affected. The sporotrichin test was positive in 117 of 131 cases. The causative organism was demonstrated in tissue sections in 69% of the cases. 相似文献
7.
8.
During a 10-year long term study, 6 eye-witnessed and 1 pressumed cases of abortions occurred in 3 one-male bisexual troops
of free ranging langurs (Presbytis entellus) near Jodhpur, Rajasthan, India. The age of the unborns varied from 35 to about 200 days. The subsequent birth interval ranged
between 7.1–21.1 months. 2 miscarriages occurred during stable periods of residency of a single male. 5 cases occurred prior
to or after infanticide in connection with male changes. In one case a female was attacked by the new male before she aborted.
In one case a female presumably aborted after attacks on her semiweaned infant. Most of the reproductive losses hence seem
to be related to psychical and physical stress exerted by new males on pregnant females. As part of their reproductive strategy,
males reduce their waiting time to insemination in this way. Abortions may likewise represent an adaptive reproductive strategy
of females, who prefer to abort instead of investing in a foetus which is likely to be killed after birth. 相似文献
9.
Genetic instability is very common amongStreptomyces strains and the affected strains display several distinctive phenotypes. In several cases DNA rearrangements, specifically
deletions and amplifications of specific segments of DNA, were demonstrated. Depending upon the reproducible amplification
of a segment in independent isolates one could predict the basic structural elements involved in the amplification process.
In the case ofS. lividans 66,5.7 kb amplifiable DNA sequence is located near the end of the linear chromosome. Amplification of this sequence and deletion
of the chromosome linked to it leads to the creation of a new end or in some cases even circularisation of the chromosome
occurs. A model incorporating these aspects is discussed. The possible involvement of proteins encoded by the amplifiable
region is also discussed. 相似文献
10.
Lisa M. Schloegel Jean-Marc Hero Lee Berger Rick Speare Keith McDonald Peter Daszak 《EcoHealth》2006,3(1):35-40
Infectious diseases are increasingly recognized as the cause of mass mortality events, population declines, and the local
extirpation of wildlife species. In a number of cases, it has been hypothesized that pathogens have caused species extinctions
in wildlife. However, there is only one definitively proven case of extinction by infection, and this was in a remnant captive
population of a Polynesian tree snail. In this article, we review the potential involvement of infectious disease in the recent
extinction of the sharp-snouted day frog Taudactylus acutirostris. Our review of available evidence suggests that a virulent pathogen of amphibians, Batrachochytrium dendrobatidis, caused a rapid, catastrophic decline of this species, from which it did not recover. We propose that this is the first case
of extinction by infection of a free-ranging wildlife species where disease acted as both the proximate and ultimate cause
of extinction. This highlights a probable underreporting of infectious disease as a cause of biodiversity loss historically
and currently. 相似文献
11.
Shivaprakash MR Rao P Mandal J Biswal M Gupta S Ray P Chakrabarti A 《Mycopathologia》2007,163(5):267-274
Nocardiosis, an uncommon infection of the past, is being increasingly reported in recent years with rise of immunosuppressed
patients. In India, very few centers have reported this disease. The present report describes twelve consecutive cases of
nocardiosis reported over a period of 26 months (January 2004 to March 2006) from a tertiary care center in north India. The
patients were predominantly males (75%) with age range of 8–65 years and mean age of 38.4 years. Eleven patients had known
underlying illness including renal transplantation, human immunodeficiency virus infection, and long-term steroid therapy.
One patient with cerebral nocardiosis had no detectable predisposing factor. Infection involved central nervous system (3
cases), lungs (5 cases), subcutaneous tissue (1 case), and anterior mediastinum (1 case). Disseminated infection was documented
in two patients. Nocardia asteroides complex was incriminated in six patients, N. brasiliensis in five and N. otitidiscaviarum in one patient. All the isolates were sensitive to co-trimoxazole, amikacin, cefotaxime and imipenem. Good therapeutic response
was observed in 10 (90.9%) of 11 patients treated with antibiotics including co-trimaxazole, cephalosporins, amikacin, and
imipenem alone or in combination. The series of nocardiosis reported from India has also been reviewed. 相似文献
12.
Godoy P Reyes E Silva V Nunes F Tomimori-Yamashita J Zaror L Fischman O 《Mycopathologia》2004,157(3):273-276
Nattrassia mangiferae formerly known as Hendersonula toruloidea,is a phaeoid coelomycete described by Nattrass in 1933. We report five casesof N. mangiferae infections in São Paulo, Brazil. This fungus wasisolated from interdigital lesions on the feet in one patient, toenails in threecases and fingernails in the other one. The infections were initially consideredto be caused by a dermatophyte. Although there are only a few cases describedin the medical literature, the five cases reported suggest that N. mangiferaeshould be taken into consideration in the differential diagnosis of tinea pedisinfections. 相似文献
13.
In a previous study on the RFLP analysis of the maize anther culture response (Wan et al. 1992), some of the anther-derived callus Unes from hybrids H99 x Pa91 (HP) and H99 x FR16 (HF) showed the same RFLP patterns with 58 (for HP Unes) or 35 (for HF lines) RFLP markers used. Since the callus Unes with the identical RFLP pattern were initiated from individual embryo-like structures (ELSs) from the same anther culture plate, these must have originated from the same microspore. Twin embryos which apparently had originated from the same microspore were also observed. Thus in certain cases one microspore must be capable of forming more than one ELS. However, in the case of the callus Unes from a different F1 hybrid (Pa91 x FR16), no identical RFLP patterns were observed. Thus multiple ELS formation from a single microspore may be genetically controlled. Since in some cases the proportion of callus lines resulting from multiple ELS formation can be quite high (about 50% for the HP lines), estimates of gene segregation and anther culture response frequencies can be affected greatly. 相似文献
14.
An outbreak of blastomycosis in Eastern Tennessee 总被引:1,自引:1,他引:0
Most cases of blastomycosis are sporadic and only nine outbreaks representing a total of 112 cases have previously been reported. Less than half of these have been culture proven cases. Outbreaks have previously occurred in North Carolina, Minnesota, Illinois, Wisconsin and Virginia. We report three culturally confirmed cases of blastomycosis from Elizabethton, Tennessee, who had onset of illness within a one-week span of time. The patients presented with fever, chest pain, weight loss, poor appetite and myalgia. Each initially had a dry cough which became productive of purulent sputum as the illness progressed. Mild hemoptysis occurred during each patient's course. Serologic testing by immunodiffusion and enzyme immunoassay were positive and testing by complement fixation was negative in each case. The diagnosis was made by histopathology on transbronchial biopsy or transthoracic needle aspiration material. Each patient improved on ketoconazole therapy. 相似文献
15.
A 55-year old man without immunosuppression clinically showed a coin lesion in the right lower lung on the chest radiographs.Aspergillus nidulans was isolated and identified in both trans-bronchial lung biopsy specimen and resected tissue. The specimens revealed characteristics of chronic necrotizing pulmonary aspergillosis pathologically. Very few reports on cases of pulmonary aspergillosis due toA. nidulans exist, and we were not able to find any reports of similar cases. This case may be the first reported case of chronic necrotizing pulmonary aspergillosis due toA. nidulans. 相似文献
16.
S. H. Rogstad 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(7-8):824-830
Oligomers (16–26 mers) composed of short, tandemly repeated DNA sequences (3–10 bases) were used individually with their complementary oligomer in separate polymerase chain reactions (PCRs) that extended the number of repeats to make 15 different PCR synthetic tandem-repeat (STR) probes. These PCR-STR probes were used to examine the inheritance of variable-number tandem-repeat (VNTR) genetic markers from two parent plants of turnip (Brassica rapa L.) to 20 offspring. Following HinfI digestion and PCR-STR probing of Southern blots, interpretable variable parental and offspring band profiles were found with 9 of the 15 probes used. Each of these nine probes produced a unique set of fragments, and no cases of different probes revealing the same fragment were detected. Seventy-nine parental fragments were found and, of these, 65% (51) appeared to be heterozygous in one or both parents, with 52% (41) appearing to be heterozygous in one of the parents exclusively. That these fragments are transmitted as though heterozygous in the parents implies that they are derived from the nuclear complement of the genome. Chi-square analyses of the transmission of markers are, in general, consistent with Mendelian expectations, although three non-parental bands were found accounting for approximately 0.5% of these transmitted bands. For the fragments heterozygous in one of the parents exclusively, seven alleles exhibited complete linkage in three groups, 12 alleles were incompletely linked in six groups, and four allelic groups involving 11 alleles were identified. PCR-STR probes are relatively rapid to generate and apply (no cloning, clone screening, or sequencing steps are required), and have been shown to reveal VNTR genetic markers in a wide variety of plant species. These results add to the list of studies showing that VNTR genetic markers (and in this case, markers revealed by PCR-STR probes) are transmitted for the greater part in a Mendelian fashion. 相似文献
17.
Inno Salasoo 《Plant Systematics and Evolution》1989,163(1-2):71-79
Alkane distribution patterns were determined in the epicuticular wax of the leaves of 13 species and a hybrid fromEricaceae and one species ofEmpetrum (Empetraceae). As chemotaxonomic indicators, the results are of limited use only. The most uniform genus wasRhododendron, the most heterogeneousVaccinium. The dominant effect of genetic over environmental factors was apparent in most cases. 相似文献
18.
The first author is allergic to skin contact with mushrooms of Suillus americanus, S. granulatus, S. grevillei, S. luteus, or S. neoalbidipes. Symptoms develop between one and two days after contact and last for approximately a week, disappearing completely without treatment. Symptoms consist of reddening, swelling, and itching, at the sites of contact with pileus cuticle mucilage of all five species. Pore layer tissues (tested for S. americanus and S. luteus) also produced strong reactions, as did pileus trama (tested for S. luteus). Spores from spore prints (tested for S. americanus and S. luteus) produced no reaction. The reaction can be avoided by wearing gloves when handling allergenic species and by washing hands promptly after working with these species. Similar cases, reported from North America, Europe, and Russia, involve Agaricus, Boletus, Lactarius, Paxillus, Ramaria, and Suillus species. Several cases involve allergy to multiple species or genera. Symptom severity varies, presumably with intensity of exposure. In one case, symptoms were renewed following ingestion. Most cases demonstrate delayed allergic contact sensitivity. 相似文献
19.
Vázquez-Tsuji O Campos-Rivera T Ahumada-Mendoza H Rondán-Zárate A Martínez-Barbabosa I 《Mycopathologia》2005,159(3):331-337
Objective. To present a series of neonates with renal fungus balls diagnosed by ultrasonography, urine culture and/or by the detection of Candida pseudomycelium in urine. Patients and methods. We revised the clinical records of neonates for whom the diagnosis of renal fungus ball was established by ultrasound and laboratory studies; these patients had been hospitalized at the National Institute of Pediatrics in Mexico between January 1st, 1999 and December 31st, 2002. Results. During the study period, 9 neonates were diagnosed with renal fungus ball. In 7 cases, the ethiologic agent was Candida albicans; whereas it was C. tropicalis in one case and C. parapsilosisin the other. Urine culture was positive (10,000 UFC/ml) in 8 cases, whereas the fungal density was only 2400UFC/ml in the last sample. Pseudohyphae were present in all cases and ultrasonography showed fungus ball in every case. All patients received a single antifungal drug, either amphotericin B or fluconazole. All the patients recovered and none of them required surgical treatment. Control postreatment by ultrasound studies showed that the fungus balls had disappeared in every case. Conclusion. The diagnosis of Candida renal fungus balls based on the ultrasound study and urine culture is also substantiated by the detection of pseudomycelium in the centrifugation pellet of urine samples, which is a fast diagnostic method. This approach permitted an early diagnosis and treatment of Candida renal fungus balls. 相似文献
20.
Wolfgang Ostendorp 《Oecologia》1991,86(1):119-124
Summary The development of lakeside fringes of Phragmites reeds can be affected by high water levels, leading in extreme cases to die-back. A model is presented that allows estimation of the proportions of the damage. The model-formulated for 1 year and one Phragmites stalk—is based on the growth curve of the stalk, the altitude of the growth site, and the water level curve for the year. Applied to a reed stand over a series of years, the model is based upon the frequency distribution of the critical stalk length and the chance that the water level will be below a given value, each parameter being time dependent. Three case studies from Lake Constance-Untersee provide an example of the significance of episodic high water levels. Hence, aestival high water levels are expected to be one of the main factors controlling the lakeside frontline of the reedbelt. The model can be used in waterworks engineering, where reed plantations are to be established on the shores of lakes and reservoirs with strongly fluctuating water levels. 相似文献