The Performance of International Equity Portfolios

This paper evaluates the ability of U.S. investors to allocate their foreign equity portfolios across 44 countries over a 25-year period. We find that U.S. portfolios achieved a significantly higher Sharpe ratio than foreign benchmarks, especially since 1990. We test whether this strong performance owed to trading expertise or longer-term allocation expertise. The evidence is overwhelmingly against trading expertise. While U.S. investors did abstain from momentum trading and instead sold past winners, we find no evidence that these past winners subsequently underperformed. In addition, conditional performance measures, which directly test reallocating into (out of) markets that subsequently outperformed (underperformed), suggest no significant trading expertise. In contrast, we offer strong evidence of longer-term allocation expertise: If we fix portfolio weights at the end of 1989 and do not allow reallocations, we still find superior performance in the recent period.

European Cyber Security System

Nowadays computer networks are widely spread in all spheres of human life. That is why the problem of cyber security of mankind is of great importance. Today, the European Union makes efforts to guarantee network safety in Europe by means of increase its member states in power and international cooperation in cyber security, including non-member countries, to prevent cyber crimes. Striving to join the European Union, Ukraine is involved in the process of providing cyber security. This paper examines the main strategies of EU standards in cyber security to be followed by Ukraine as one of European countries

High Resolution Near-Infrared Spectra of Protostars

We present new high resolution (R = 21,000) near-infrared (2 microns) spectroscopic observations of a sample of Class I and flat-spectrum protostellar objects in the rho Ophiuchi dark cloud. None of the five Class I spectra show CO v = 0 -- 2 absorption features, consistent with high K-band continuum veilings, 4 <= r_k <= 20 and fast stellar rotation, assuming that the underlying protostellar photospheres are of late spectral type, as is suggested by the low luminosities of most of these objects. Two of the flat-spectrum protostellar objects also show no absorption features and are likely to be highly veiled. The remaining two flat-spectrum sources show weak, broad absorptions which are consistent with an origin in quickly rotating (v sin i ~ 50 km / s) late-type stellar photospheres which are also strongly veiled, r_k = 3 - 4. These observations provide further evidence that: 1)-Class I sources are highly veiled at near-infrared wavelengths, confirming previous findings of lower resolution spectroscopic studies; and 2)- flat-spectrum protostars rotate more rapidly than classical T Tauri stars (Class II sources), supporting findings from a recent high resolution spectroscopic study of other flat-spectrum sources in this cloud. In addition our observations are consistent with the high rotation rates derived for two of the Class I protostellar objects in our sample from observations of variable hard X-ray emission obtained with the ASCA satellite. These observations suggest that certain Class I sources can rotate even more rapidly than flat-spectrum protostars, near breakup velocity.Comment: 16 pages including 2 tables and 2 figures (AASTeX 5.x) to be published in The Astronomical Journal July 200

The Performance of International Equity Portfolios

This paper evaluates the ability of U.S. investors to allocate their foreign equity portfolios across 44 countries over a 25-year period. We find that U.S. portfolios achieved a significantly higher Sharpe ratio than foreign benchmarks, especially since 1990. We test whether this strong performance owed to trading expertise or longer-term allocation expertise. The evidence is overwhelmingly against trading expertise. While U.S. investors did abstain from momentum trading and instead sold past winners, we find no evidence that these past winners subsequently underperformed. In addition, conditional performance measures, which directly test reallocating into (out of) markets that subsequently outperformed (underperformed), suggest no significant trading expertise. In contrast, we offer strong evidence of longer-term allocation expertise: If we fix portfolio weights at the end of 1989 and do not allow reallocations, we still find superior performance in the recent period.momentum, contrarian, conditional performance measures, equities, home bias

A Metabolic Dependency for Host Isoprenoids in the Obligate Intracellular Pathogen Rickettsia parkeri Underlies a Sensitivity to the Statin Class of Host-Targeted Therapeutics.

Gram-negative bacteria in the order Rickettsiales have an obligate intracellular growth requirement, and some species cause human diseases such as typhus and spotted fever. The bacteria have evolved a dependence on essential nutrients and metabolites from the host cell as a consequence of extensive genome reduction. However, it remains largely unknown which nutrients they acquire and whether their metabolic dependency can be exploited therapeutically. Here, we describe a genetic rewiring of bacterial isoprenoid biosynthetic pathways in the Rickettsiales that has resulted from reductive genome evolution. Furthermore, we investigated whether the spotted fever group Rickettsia species Rickettsia parkeri scavenges isoprenoid precursors directly from the host. Using targeted mass spectrometry, we found that infection caused decreases in host isoprenoid products and concomitant increases in bacterial isoprenoid metabolites. Additionally, we report that treatment of infected cells with statins, which inhibit host isoprenoid synthesis, prohibited bacterial growth. We show that growth inhibition correlates with changes in bacterial size and shape that mimic those caused by antibiotics that inhibit peptidoglycan biosynthesis, suggesting that statins lead to an inhibition of cell wall synthesis. Altogether, our results describe a potential Achilles' heel of obligate intracellular pathogens that can potentially be exploited with host-targeted therapeutics that interfere with metabolic pathways required for bacterial growth.IMPORTANCE Obligate intracellular pathogens, which include viruses as well as certain bacteria and eukaryotes, are a subset of infectious microbes that are metabolically dependent on and unable to grow outside an infected host cell because they have lost or lack essential biosynthetic pathways. In this study, we describe a metabolic dependency of the bacterial pathogen Rickettsia parkeri on host isoprenoid molecules that are used in the biosynthesis of downstream products, including cholesterol, steroid hormones, and heme. Bacteria make products from isoprenoids, such as an essential lipid carrier for making the bacterial cell wall. We show that bacterial metabolic dependency can represent a potential Achilles' heel and that inhibiting host isoprenoid biosynthesis with the FDA-approved statin class of drugs inhibits bacterial growth by interfering with the integrity of the cell wall. This work supports the potential to treat infections by obligate intracellular pathogens through inhibition of host biosynthetic pathways that are susceptible to parasitism