Management Practices to Reduce Losses Caused by Hail Damage to Burley Tobacco

It is estimated that Kentucky farmers have suffered income losses caused by hail damage to burley tobacco in excess of $6 million annually over the last five years . Such losses could often be substantially reduced through proper management of the crop following hail, according to studies involving artificial and natural hail damage

Dividing population genetic distance data with the software Partitioning Optimization with Restricted Growth Strings (PORGS): an application for Chinook salmon (Oncorhynchus tshawytscha), Vancouver Island, British Columbia

A new method of finding the optimal group membership and number of groupings to partition population genetic distance data is presented. The software program Partitioning Optimization with Restricted Growth Strings (PORGS), visits all possible set partitions and deems acceptable partitions to be those that reduce mean intracluster distance. The optimal number of groups is determined with the gap statistic which compares PORGS results with a reference distribution. The PORGS method was validated by a simulated data set with a known distribution. For efficiency, where values of n were larger, restricted growth strings (RGS) were used to bipartition populations during a nested search (bi-PORGS). Bi-PORGS was applied to a set of genetic data from 18 Chinook salmon (Oncorhynchus tshawytscha) populations from the west coast of Vancouver Island. The optimal grouping of these populations corresponded to four geographic locations: 1) Quatsino Sound, 2) Nootka Sound, 3) Clayoquot +Barkley sounds, and 4) southwest Vancouver Island. However, assignment of populations to groups did not strictly reflect the geographical divisions; fish of Barkley Sound origin that had strayed into the Gold River and close genetic similarity between transferred and donor populations meant groupings crossed geographic boundaries. Overall, stock structure determined by this partitioning method was similar to that determined by the unweighted pair-group method with arithmetic averages (UPGMA), an agglomerative clustering algorithm

Oroszországból szeretettel: Az Ikarusz esete és a magyar autóbuszgyártás

A szerző nemcsak a priori kérdőjelezi meg az akkulturáció fogalmát, hanem különösen annak alkalmazhatóságát vitatja az átalakítás jelenlegi fázisában levő magyar gazdaságra. Ennek érdekében a tanulmány kimutatja, hogy a minőség kérdése egyelőre még csak csírájában van meg Magyarország egyik legjelentősebb gyártó vállalatánál, az IKARUSZ Karosszéria és Járműgyárban. Következésképp az akkulturáció kérdései ennél a vállalatnál a legjobb esetben is csak kezdetleges állapotban vannak, a legrosszabb esetben pedig utat nyitnak a potenciálisan idegen gyakorlat legitimációja felé a kelet-közép- európai gazdaságokban

The effects of tectonic release on short-period P waves from NTS explosions

The first cycle (ab amplitude) of teleseismic short-period P waves from underground nuclear explosions at Pahute Mesa (NTS) show a systematic azimuthal amplitude pattern that can possibly be explained by tectonic release. The amplitudes vary by a factor of three, with diminished amplitudes being recorded at azimuths around N25°E. This azimuthal pattern has a strong sin(2φ) component and is observed, to varying degrees, for 25 Pahute Mesa events, but not for events at other sites within the NTS. Events that are known to have large tectonic release have more pronounced sin(2φ) amplitude variations. A synthesis of long-period body and surface wave investigations of tectonic release for Pahute Mesa events shows that, in general, the nonisotropic radiation is equivalent to nearly vertical, right-lateral strike-slip faulting trending from N20°W to due north. Long-period P waves at upper mantle distances demonstrate that there is a significant high-frequency component to the tectonic release. Using the long-period constraints on orientation, moment, and frequency content of the tectonic release, the expected short-period P wave effects are predicted. For models in which the downgoing P wave from the explosion triggers tectonic release within a few kilometers below the shot point, a factor of 2.5 amplitude variation with azimuth is predicted for the short-period ab amplitudes, with the lowest amplitudes expected near N25°E. Rather subtle azimuthal variations in the waveforms are expected, particularly for downward propagating ruptures, which is consistent with the absence of strong variations in the data. The occurrence of the azimuthal pattern, albeit with varying strength, for all of the Pahute Mesa events suggests a tectonic release model in which the shatterzone surrounding the explosion cavity is extended preferentially downward by driving a distributed network of faults and joints underlying the Mesa several kilometers beneath the surface. In this model, all events could have a component of tectonic release which would reflect the regional stress regime, although there may be slight spatial and temporal variations in the tectonic release contribution. Some events may trigger slip on larger throughgoing faults as well. While it is shown that tectonic release can affect teleseismic short-period signals significantly, and may contribute to the Pahute Mesa amplitude pattern, other possible explanations are considered

Teleseismic analysis of the 1980 Mammoth Lakes earthquake sequence

The source mechanisms of the three largest events of the 1980 Mammoth Lakes earthquake sequence have been determined using surface waves recorded on the global digital seismograph network and the long-period body waves recorded on the WWSSN network. Although the fault-plane solutions from local data (Cramer and Toppozada, 1980; Ryall and Ryall, 1981) suggest nearly pure left-lateral strike-slip on north-south planes, the teleseismic waveforms require a mechanism with oblique slip. The first event (25 May 1980, 16^h 33^m 44^s) has a mechanism with a strike of N12°E, dip of 50°E, and a rake of −35°. The second event (27 May 19^h 44^m 51^s) has a mechanism with a strike of N15°E, dip of 50°, and a slip of −11°. The third event (27 May, 14^h 50^m 57^s) has a mechanism with a strike of N22°E, dip of 50°, and a rake of −28°. The first event is the largest and has a moment of 2.9 × 10^(25) dyne-cm. The second and third events have moments of 1.3 and 1.1 × 10^(25) dyne-cm, respectively. The body- and surface-wave moments for the first and third events agree closely while for the second event the body-wave moment (approximately 0.6 × 10^(25) dyne-cm) is almost a factor of 3 smaller than the surface-wave moment. The principal axes of extension of all three events is in the approximate direction of N65°E which agrees with the structural trends apparent along the eastern front of the Sierra Nevada

A discrepancy between long- and short-period mechanisms of earthquakes near the Long Valley caldera

The largest events in the 1980 Mammoth Lakes earthquake sequence show a discrepancy between fault mechanisms which are determined on the basis of the local short-period first motions and those determined by modeling of long-period regional and teleseismic waveforms. The short-period solutions are left-lateral strike-slip on north-striking, near vertical planes. The long-periods invariably require a much more moderately dipping fault plane with a significant dip-slip (normal) component. Persistence of disagreements between short- and long-period polarities to teleseismic distances suggests that the source-time functions are complicated and may be responsible for at least part of the discrepancy. In addition, there seems to be a systematic difference between local short-period polarities and teleseismic long-period polarities that is related to travel paths across portions of Long Valley Caldera. It is possible that a low velocity zone related to recent magmatic activity is causing the deflection of local seismic rays, thus distorting the fault plane projection

A broadband study of the 13 August 1978 Santa Barbara earthquake

The Santa Barbara earthquake of 13 August 1978, provides an opportunity to perform a broadband investigation of body waves for a well-recorded, moderate size (M_L = 5.1) event. The long- and short-period teleseismic body waves are modeled in the time domain to construct a source time function which is consistent in the period range of 1 to 20 sec. The long-period records indicate an overall duration of 6 sec while the short-period records reveal the fine-scale character of the slip history consisting of two sharp pulses separated by about 1 sec. The source mechanism determined from this analysis is a moderately dipping (30°NE) thrust with significant left-lateral slip. The moment was determined to be 1.1 × 10^(25) dyne-cm. The earthquake was also reasonably well recorded on accelerographs in the near-field. The modeling of the strong motion displacements was a two step procedure: (1) the displacements were modeled alone, and (2) in an attempt to achieve consistency between the local and far-field time functions, the qualitative features of the teleseismic short-period time function were used to predict the displacements. If the two sources in the short-period time function are allowed to have different mechanisms, the displacements can be modeled quite well. This suggests that the overall faulting process was rough, and the multiple source character suggested at high frequencies is due to high-stress drop asperities. The two sources are modeled as asperities separated by 1.5 km; the first source has a mechanism consistent with the teleseismic solution while the second source is more steeply dipping. The total moment determined from the strong motion data is 3.5 × 10^(24) dyne-cm or one-third the long-period moment. This is consistent with other recent studies which suggest that the high-frequency strong ground motion is controlled by the distribution of asperities even though the sum of their moments may be small compared to the overall moment. This study also shows the importance of teleseismic short periods in predicting the local displacements