Demographic supply-demand imbalance in industrial structure in the super-aged nation Japan

Background

Japan has a rapidly decreasing population, with ultra-low fertility and extremely fast aging. The rapid dynamics constitute a warning that change in the industrial structure may be unable to meet the changing pace of age-dependent demand.

Methods

The present study estimated the supply-demand imbalance by industrial sector, and we investigated the effectiveness of possible countermeasures. To quantify the demographic burden of different industry experts, we employed the dependency ratio to calculate the supply and demand of each industrial sector and occupation.

Results

We identified an expected excess of demand in the health-care sector; the growth in that deficiency is likely to continue until 2045, when the elderly population is likely to reach a peak. By contrast, oversupply is expected in the education and construction sectors. An overall shortage of full-time workers is likely to continue until 2050, when we predict that Japan will lack 3.1–9.3 million full-time workers to satisfy the baseline demand level.

Conclusions

Considering that the imbalance is evident over different sectors, interministerial regulation of occupational choice may need to be imposed, e.g., by drastically changing student sizes in different area of higher education. Japan may have to decide to downgrade its social services and potentially consider increasing immigrant workers.

     

Inhibitory effects of newly synthesized sulfonamide derivatives on calmodulin-dependent phosphodiesterase activity and their modulation of the external ATP-dependent permeability change in mammalian cultured cells

External ATP causes a passive permeability change in several types of transformed cells and this change is further enhanced by calmodulin antagonists, such as trifluoperazine. However, such drugs also have nonspecific effects on membrane permeability. We have synthesized several new sulfonamide derivatives, which were found to inhibit calmodulin-dependent phosphodiesterase. The drugs also enhanced the ATP-dependent permeability change in CHO-K1 cells, but their effective concentration ranges were wider than those of previously known antagonists, and thus they would be useful for pharmacological use.     

Substance P-like immunoreactivity in the trigeminal sensory nuclei of an infrared-sensitive snake,Agkistrodon blomhoffi

Summary With the peroxidase-antiperoxidase immunohistochemical method we ascertained the presence of substance P-like immunoreactivity (SPLI) in fibers and cell bodies of the trigeminal sensory system of the pit viper, Agkistrodon blomhoffi. There are a few SPLI fibers each in the principal sensory nucleus and the main neuropil of the lateral descending nucleus (i.e., the infrared sensory nucleus); a moderate number in the descending nucleus; and a large number in the caudal subnucleus, the medial edges of the interpolar subnucleus, and the marginal neuropil of the lateral descending nucleus. About 30% of the cell bodies in the ophthalmic and maxillo-mandibular ganglia show SPLI, and of the two craniocervical ganglia, the proximal ganglion has many more cells with SPLI than the distal ganglion. The SPLI distribution in the common trigeminal sensory system is similar to that of mammals, and suggests that the function of this system is also similar. In the infrared sensory system, the differing distribution in the main and marginal neuropils suggests separate functions for these two structures in the system.     

Prevalence of human immunodeficiency virus (HIV) infection among hemophiliacs in Fukuoka, Japan

To determine when the hemophiliacs in Fukuoka prefecture, Japan, first became positive for antibodies, we tested human immunodeficiency virus (HIV) antibodies on serum samples obtained from 1976-1987 stored at -30 C. Fifteen out of 64 hemophilia A patients (23.4%), five out of 11 hemophilia B patients (45.5%), but none of 17 patients with von Willebrand's disease (0%) were positive for HIV antibodies. In this series, two with hemophilia A became positive for HIV antibodies for the first time in 1983, and in 1984 another four with hemophilia A and one with hemophilia B became positive.     

Destruction of organelle nuclei during spermatogenesis inChara corallina examined by staining with DAPI and anti-DNA antibody

Summary The behavior of plastid and mitochondrial nuclei (synonymous with nucleoids) during spermatogenesis inChara corallina was examined by fluorescence microscopy after staining with 4,6-diamidino-2-phenylindole (DAPI). These organelle nuclei, which were present in internode cells and cells at the early spermatid stage, disappeared during spermatogenesis. This conclusion was confirmed by immunofluorescence microscopy using of a monoclonal anti-DNA antibody. The pattern of fluorescence obtained using the antibody coincided with that obtained by staining with DAPI. These results suggest that the disappearance of nuclei from male-derived organelles is most likely to result in maternal inheritance inChara corallina.     

Formation of new cortico-rubral synapses as a possible mechanism for classical conditioning mediated by the red nucleus in cat

1.) By extracellular and intracellular recordings of the red nucleus (RN) cell activity, we investigated enhancement of signaling effectiveness at the cortico-rubral synapses underlying the establishment of classical conditioning mediated by RN in the cat. The classical conditioning of forelimb flexion was produced by pairing the conditioned stimulus (CS) to the cerebral peduncle (CP) with the unconditioned stimulus (US) to the forelimb skin at an interval of 100 msec for about a week. 2.) The increased responsiveness of RN cells to the CS was correlated with acquisition of the conditioned forelimb flexion, i.e. RN cells responded to the CS with higher firing probability in the animals which received the paired conditioning than those in the animals which received the CS alone or pairing of the CS and the US at random intervals or those in the naive animals which did not receive any training. 3.) Monosynaptic excitation of RN cells in response to the single pulse to CP was most enhanced in the animals which received the paired conditioning. By contrast, response of RN cells, as well as the behavioral response, induced by stimulation of the cerebellar interpositus nucleus (IP) was not enhanced after the paired conditioning. The difference between the responses to the stimulation of CP and IP suggested that the primary site of neuronal change is the cortico-rubral synapses. 4.) In the animals that received the paired conditioning, the excitatory postsynaptic potentials (EPSPs) induced by stimulation of CP had fast-rising components superimposed on the normal slow-rising EPSPs. On the other hand, most of the CP-EPSPs recorded in the naive animals showed a slow time course. The slow time course of the CP-EPSPs has been attributed to the peripheral localization of the cortico-rubral synapses on the dendrites of RN cells. 5.) The electrotonic length of RN cells in the animals which received the paired conditioning was not shorter than that in the naive animals. Therefore, it was suggested that the appearance of the fast-rising component in the CP-EPSPs is cause by formation of the new cortico-rubral synapses on proximal portions of the soma-dendritic membrane of RN cells. 6.) Since it has been established that new synapses formed by collateral sprouting are retained for more than several months, the formation of new synaptic connections could underlie long-lasting behavioral modification.     

Involvement of Calcineurin in Ca2+ Paradox-Like Injury of Cultured Rat Astrocytes

Abstract: The Ca²⁺/calmodulin-dependent phosphatase calcineurin may have physiological and pathological roles in neurons, but little is known about the roles of the enzyme in glial cells. We have previously reported that reperfusion of cultured astrocytes in Ca²⁺-containing medium after exposure to Ca²⁺-free medium caused Ca²⁺ influx followed by delayed cell death. In this study, we examined if calcineurin is involved in this Ca²⁺-mediated astrocytic injury. FK506, an inhibitor of calcineurin, protected cultured rat astrocytes against paradoxical Ca²⁺ challenge-induced injury in a dose-dependent manner (10⁻¹⁰–10⁻⁸ M ). Cyclosporin A at 1 µ M mimicked the effect of FK506. Rapamycin (1 µ M ) did not affect astrocyte injury, but it blocked the protective effect of FK506. Deltamethrin (20 n M ), another calcineurin inhibitor, had a similar protective effect, whereas okadaic acid did not. FK506 affected neither paradoxical Ca²⁺ challenge-induced increase in cytosolic Ca²⁺ level nor Na⁺-Ca²⁺ exchange activity in the cells, suggesting that the calcineurin is involved in processes downstream of increased cytosolic Ca²⁺ level. Immunochemical studies showed that both calcineurin A (probably the Aβ2 isoform) and B subunits were expressed in the cells. It is concluded that calcineurin is present in cultured astrocytes and it has a pathological role in the cells.     

Food and daily food consumption of southern minke whales in the Antarctic

Summary The stomach contents of 273 southern minke whales (Balaenoptera acutorostrata) taken in the region 55°S to the ice-edge and between 105°E and 115°E by a Japanese survey during 1987/88 were examined. The minke whales' dominant feeding ground coincided with a distinctive hydrographic front in the vicinity of the ice-edge at the mouth of Vincennes Bay. Krill (Euphausia superba) were the dominant food species comprising 100% and 94% by weight of stomach contents in the ice-edge and offshore zones, respectively. In the offshore zone, minke whales tend to feed on E. superba rather than Thysanoessa macrura, which is found more frequently than the former in net samples. Total food consumption by minke whales per day was estimated to be 1170 t (22.1 kg/km²) and 596 t (2.0 kg/km²) in the ice-edge and offshore zones, respectively. Feeding activity peaked in the early morning in the ice-edge zone, whereas it occurred irregularly throughout the day in the offshore zone. Two size modes of krill (25–28 mm in body length (1 year-old) and 41–48 mm (3–4 year-old)) dominated the diet. Although the former was numerically more abundant, the latter dominated the diet by weight, suggesting that larger krill are more important food for minke whales. Observed spatial pattern of krill populations in the study region suggests that movement of the subsurface cold water mass tended to carry krill offshore from the ice-edge.The earlier version of this paper was submitted to the 42nd Meeting of the Scientific Committee of International Whaling Commission as SC/42/SHM; 34.     

Characterization of C-4-methylated sterols by pyridine-induced solvent shifts in proton magnetic resonance spectroscopy

The proton magnetic resonance (PMR) spectra were measured in deuterochloroform (CDCl₃) and pyridine solutions for some 4-desmethyl, 4α-methy1, 4β-methyl, and 4,4-dimethyl sterols related to 5α-cholestane series as well as for their C-3-oxo derivatives. The influence of pyridine, relative to CDCl₃, on methyl group chemical shifts was discussed. The technique utilizing pyridine-induced solvent shifts in PMR spectroscopy was found useful in characterizing the individual classes of sterols.