Long-Term Population Dynamics of Namib Desert Tenebrionid Beetles Reveal Complex Relationships to Pulse-Reserve Conditions.

Noy-Meir's paradigm concerning desert populations being predictably tied to unpredictable productivity pulses was tested by examining abundance trends of 26 species of flightless detritivorous tenebrionid beetles (Coleoptera, Tenebrionidae) in the hyper-arid Namib Desert (MAP = 25 mm). Over 45 years, tenebrionids were continuously pitfall trapped on a gravel plain. Species were categorised according to how their populations increased after 22 effective rainfall events (>11 mm in a week), and declined with decreasing detritus reserves (97.7-0.2 g m-2), while sustained by nonrainfall moisture. Six patterns of population variation were recognised: (a) increases triggered by effective summer rainfalls, tracking detritus over time (five species, 41% abundance); (b) irrupting upon summer rainfalls, crashing a year later (three, 18%); (c) increasing gradually after series of heavy (>40 mm) rainfall years, declining over the next decade (eight, 15%); (d) triggered by winter rainfall, population fluctuating moderately (two, 20%); (e) increasing during dry years, declining during wet (one, 0.4%); (f) erratic range expansions following heavy rain (seven, 5%). All species experienced population bottlenecks during a decade of scant reserves, followed by the community cycling back to its earlier composition after 30 years. By responding selectively to alternative configurations of resources, Namib tenebrionids showed temporal patterns and magnitudes of population fluctuation more diverse than predicted by Noy-Meir's original model, underpinning high species diversity.

Widespread dieback of riparian trees on a dammed ephemeral river and evidence of local mitigation by tributary flows.

Ephemeral rivers act as linear oases in drylands providing key resources to people and wildlife. However, not much is known about these rivers' sensitivities to human activities. We investigated the landscape-level determinants of riparian tree dieback along the Swakop River, a dammed ephemeral river in Namibia, focusing on the native ana tree (Faidherbia albida) and the invasive mesquite (Prosopis spp.). We surveyed over 1,900 individual trees distributed across 24 sites along a 250 km stretch of the river. General linear mixed models were used to test five hypotheses relating to three anthropogenic threats: river flow disruption from damming, human settlement and invasive species. We found widespread dieback in both tree populations: 51% mortality in ana tree, with surviving trees exhibiting 18% canopy death (median); and 26% mortality in mesquite, with surviving trees exhibiting 10% canopy death. Dieback in the ana tree was most severe where trees grew on drier stretches of the river, where tributary flow was absent and where mesquite grew more abundantly. Dieback in the mesquite, a more drought-tolerant taxon, did not show any such patterns. Our findings suggest that dieback in the ana tree is primarily driven by changes in river flow resulting from upstream dam creation and that tributary flows provide a local buffer against this loss of main channel flow. The hypothesis that the invasive mesquite may contribute to ana tree dieback was also supported. Our findings suggest that large dams along the main channels of ephemeral rivers have the ability to cause widespread mortality in downstream riparian trees. To mitigate such impacts, management might focus on the maintenance of natural tributary flows to buffer local tree populations from the disruption to main channel flow.

Identification of a second human subtilisin-like protease gene in the fes/fps region of chromosome 15.

A cDNA encoding a novel human subtilisin-like protease was identified by a polymerase chain reaction (PCR) methodology. PCR primers were designed to be specific for the subfamily of eukaryotic subtilisin-like proteases with specificity for paried basic amino acid residue processing motifs. The gene encoding this protease, designated PACE4, also encoded a smaller subtilisin-related polypeptide derived by alternate mRNA splicing. The deduced PACE4 protein sequence contained a number of interesting features not present in other family members, including an extended signal peptide region, and a relatively large carboxyl-terminal cysteine-rich region with no obvious membrane anchor sequence. As with the fur gene product, the tissue distribution of PACE4 was widespread, with comparatively higher levels in the liver. An additional relationship to the fur gene product was shown by chromosomal localization studies. The close proximity of the fur and PACE4 genes on chromosome 15 suggests that these genes probably evolved from a common ancestor by gene duplication.

[The examination of usefulness of the disposable pump in case of cancer pain relaxation and the economic problem].

Recently, an increasing number of cancer patients being taken care of at home has been able to use morphine to treat their pain by themselves. The most suitable administration method for individual patients-oral, intravenous, subcutaneous or depository--is being investigated. When oral intake becomes difficult, the subcutaneous via of administration is best option because it is the less dangerous and easier to use compared with the other two options. These are also thought to be less useful because it is difficult to judge the exact dosage. The use of pumps might be an economic problem to some patients. We will examine this problem.

Vision in the nocturnal wandering spider Leucorchestris arenicola (Araneae: Sparassidae).

At night the Namib Desert spider Leucorchestris arenicola performs long-distance homing across its sand dune habitat. By disabling all or pairs of the spiders' eight eyes we found that homing ability was severely reduced when vision was fully abolished. Vision, therefore, seems to play a key role in the nocturnal navigational performances of L. arenicola. After excluding two or three pairs of eyes, the spiders were found to be able to navigate successfully using only their lateral eyes or only their anterior median eyes. Measurement of the eyes' visual fields showed that the secondary eyes combined have a near full (panoramic) view of the surroundings. The visual fields of the principal eyes overlap almost completely with those of the anterior lateral eyes. Electroretinogram recordings indicate that each eye type contains a single photopigment with sensitivity peaking at approximately 525 nm in the posterior and anteriomedian eyes, and at approximately 540 nm in the anteriolateral eyes. Theoretical calculations of photon catches showed that the eyes are likely to employ a combination of spatial and temporal pooling in order to function at night. Under starlit conditions, the raw spatial and temporal resolution of the eyes is insufficient for detecting any visual information on structures in the landscape, and bright stars would be the only objects visible to the spiders. However, by summation in space and time, the spiders can rescue enough vision to detect coarse landscape structures. We show that L. arenicola spiders are likely to be using temporal summation to navigate at night.

Use of local cues in the night-time navigation of the wandering desert spider Leucorchestris arenicola (Araneae, Sparassidae).

Adult male Leucorchestris arenicola can walk round-trips of several tens of meters in search of females. Most excursions end with the spiders returning to their burrow. For small animals homing over distances of several meters is theoretically impossible without the aid of external cues. It was investigated, whether the spiders use local cues or they rely solely on global cues. Individually marked male spiders were captured during their excursions and displaced several meters inside an opaque box. Ten out of twelve displaced spiders returned to their burrows. This shows that the male L. arenicola are using local cues during their homing, as the comparatively small displacement distances could not be detected by means of global, e.g. celestial cues. In order to test whether the spiders could be using olfactory guidance, the burrows were displaced by 2 m while the spiders were out on their journeys. In 12 out of 15 experiments, the spiders did not find their burrows. These results show that the burrows do not function as olfactory beacons for the homing spiders.

The night-time temporal window of locomotor activity in the Namib Desert long-distance wandering spider, Leucorchestris arenicola.

Even though being active exclusively after sunset, the male Leucorchestris arenicola spiders are able to return to their point of departure by following bee-line routes of up to several hundreds of meters in length. While performing this kind of long-distance path integration they must rely on external cues to adjust for navigational errors. Many external cues which could be used by the spiders change dramatically or disappear altogether in the transition period from day to night. Hence, it is therefore imperative to know exactly when after sunset the spiders navigate in order to find out how they do it. To explore this question, we monitored their locomotor activity with data loggers equipped with infrared beam sensors. Our results show that the male spiders are most active in the period between the end and the beginning of the astronomical twilight period. Moreover, they prefer the moonless, i.e. darkest times at night. Hence, we conclude that the males are truly-and extremely-nocturnal. We further show that they are able to navigate under the very dim light conditions prevailing on moonless nights, and thus do not have to rely on the moon or on moon-related patterns of polarised light as potential compass cues.

[An autopsy case of malignant histiocytosis showing a phenotype of S100 +lysozyme].

A 37-year-old Japanese man was admitted to our hospital because of high fever. The peripheral blood showed pancytopenia with a few erythrophagocytic histiocytes. A bone marrow aspirate revealed 12% immature histiocytes and 7% leukoerythrophagocytic histiocytes. A postmortem examination showed an infiltrative proliferation of immature histiocytes and erythrophagocytic histiocytes in the sinusoid of the liver, the urinary bladder, etc. These findings were consistent with malignant histiocytosis. In addition, these abnormal histiocytes showed a phenotype of S 100 protein +lysozyme.- In agreement with Watanabe's report, our findings suggest that malignant histiocytosis is the neoplasm of T-zone histiocytes.

Adult-onset acid maltase deficiency in siblings.

Two siblings who developed adult form acid maltase deficiency (AMD) are reported. The elder sister, a 30-year-old Japanese woman whose parents are cousins was admitted because of respiratory disturbance which she noticed two years previously. The muscle histology demonstrated numerous acid phosphatase positive vacuoles filled with PAS positive materials, and the muscle enzyme assay demonstrated a reduction of acid maltase activity, thus confirming a diagnosis of acid maltase deficiency of adult form. Her younger sister, a 25-year-old woman who had no obvious history of muscle weakness was admitted because of coma due to subarachnoideal hemorrhage and died two days later. Postmortem examination revealed the rupture of a fusiform aneurysm of the basilar artery whose wall showed vacuolar degeneration, and the histological and biochemical examination revealed that she had also AMD of the adult form. It is considered that the fragility of arterial wall, caused by vacuolar degeneration due to AMD, resulted as the rupture of aneurysm. Immunologically cross reactive material against acid maltase antibody was not detected. To our knowledge, this family is considered to be the third of AMD of the adult form reported in Japan.