Black Bear

The American black bear (Ursus americanus, Figure 1) is a challenging species for wildlife agencies to manage due to its size, intelligence, extensive range, food habits, and adaptability, as well as societal views. In North America alone, agencies receive more than 40,000 complaints about black bear annually. Black bears are known as ‘food-driven’ animals, meaning most conflicts result from a bear’s drive to meet its nutritional needs. Not surprisingly, an overwhelming proportion of conflicts are related to their use of anthropogenic (human) food sources, such as garbage, bird food, and crops. Understanding what drives human-bear conflict is the first part of good management. Methods to manage human-bear conflicts can be grouped into two general categories: proactive and reactive. Proactive management attempts to change human behavior and prevent conflict, or keep it from recurring. Examples of proactive management include removing attractants, education and awareness, and exclusion. Conversely, reactive management attempts to change bear behavior or results in the lethal removal of the bear. Prior to any management action, there are important factors that managers and homeowners should consider. First, many of the methods described herein are only permissible to licensed personnel, such as state and federal biologists and wildlife managers. It is up to the individual to know which strategies are legal by reviewing local laws and agency websites. Also, it is important to note that any action plan should consider the side effects of the action and include a system for monitoring efficacy (short and long-term reactions of the bear). Documenting the season, time of day, type of conflict, and any information about the bear(s) involved is important for monitoring results. Be aware that the removal of the offending bear may open up its territory to other bear and conflicts, if the cause of the conflict is not mitigated

Finding The Beta For A Portfolio Isn't Obvious: An Educational Example

When a portfolio is not actively managed to maintain a fixed investment percentage in each asset but rather maintains a fixed number of shares for each asset, the portfolio weights will change over time because the market returns of the different assets will not be the same.  Consequently, portfolio betas computed as a linear combination of asset betas, which is the usual practice, will be different from betas computed using regression techniques on portfolio returns as is done when evaluating individual assets and mutual funds.  The alternative approaches can result in quite different beta statistics and, consequently, inconsistent decisions depending on which method is used.&nbsp

Temperature-dependent Hall scattering factor and drift mobility in remotely doped Si:B/SiGe/Si heterostructures

Hall-and-Strip measurements on modulation-doped SiGe heterostructures and combined Hall and capacitance–voltage measurements on metal-oxide-semiconductor (MOS)-gated enhancement mode structures have been used to deduce Hall scattering factors, rH, in the Si1 – xGex two-dimensional hole gas. At 300 K, rH was found to be equal to 0.4 for x = 0.2 and x = 0.3. Knowing rH, it is possible to calculate the 300 K drift mobilities in the modulation-doped structures which are found to be 400 cm2 V – 1 s – 1 at a carrier density of 3.3 × 1011 cm – 2 for x = 0.2 and 300 cm2 V – 1 s – 1 at 6.3 × 1011 cm – 2 for x = 0.3, factors of between 1.5 and 2.0 greater than a Si pMOS control

A 3D <i>in vitro</i> model reveals differences in the astrocyte response elicited by potential stem cell therapies for CNS injury.

Aim: This study aimed to develop a 3D culture model to test the extent to which transplanted stem cells modulate astrocyte reactivity, where exacerbated glial cell activation could be detrimental to CNS repair success. Materials & methods: The reactivity of rat astrocytes to bone marrow mesenchymal stem cells, neural crest stem cells (NCSCs) and differentiated adipose-derived stem cells was assessed after 5 days. Schwann cells were used as a positive control. Results: NCSCs and differentiated Schwann cell-like adipose-derived stem cells did not increase astrocyte reactivity. Highly reactive responses to bone marrow mesenchymal stem cells and Schwann cells were equivalent. Conclusion: This approach can screen therapeutic cells prior to in vivo testing, allowing cells likely to trigger a substantial astrocyte response to be identified at an early stage. NCSCs and differentiated Schwann cell-like adipose-derived stem cells may be useful in treating CNS damage without increasing astrogliosis

Why Downside Beta Is Better: An Educational Example

An educational example is presented that is an effective teaching illustration to help students understand the difference between traditional CAPM beta and downside (or down-market) beta and why downside beta is a superior measure for use in personal financial planning investment policy statements

Asset Attribution Stability And Portfolio Construction: An Educational Example

This paper illustrates how a third statistic from asset pricing models, the R-squared statistic, may have information that can help in portfolio construction. Using a traditional CAPM model in comparison to an 18-factor Arbitrage Pricing Style Model, a portfolio separation test is conducted. Portfolio returns and risk metrics are compared using data from the Dow Jones 30 stocks over the period January 2007 through October 2013. Various teaching points are discussed and illustrated