Time of dehairing alters pork quality development.

Studies investigating the effect of scald time on pork quality are confounded with time of dehairing. To understand better pork quality development and two-toning in hams, twenty-four carcasses were assigned to an 8- or 16-min dwell time prior to the dehairing, with or without scalding (n = 6 per trt). Semimembranosus (SM) muscles were collected following dehairing and at 24 h postmortem. Protracted time to dehair improved ultimate pH (pHu; P < 0.005) and reduced (P < 0.05) color variation. One hundred forty-two carcasses were then subjected to protracted (control, 10-min) dwell times (15-min, or 20-min) in an industrial setting. Lightness was improved with 15-min dwell times compared to control, however 20-min dwell decreased the pHu (P < 0.001), increased lightness (P < 0.05), and percent purge (P < 0.001) in the SM. Also, lightness of the longissimus muscle (LM) increased (P < 0.001) with dwell time. These data show time to dehairing impacts pork quality development and suggest dehairing may be critical to quality development in a muscle-dependent manner.

Reduced scald time does not influence ultimate pork quality.

Fresh pork color is a function of pigment, and the pH and temperature conditions in the carcass postmortem. To explore the role of scald on color development, carcasses (n = 16) were subjected to either a 4- or 8-min scald. Semimembranosus (SM) muscle samples were collected before and after scalding, and at 24 h postmortem. A 50% reduction in scald time resulted in lighter color (L*) across the muscle early postmortem (P < 0.001), yet the 8-min scald treatment was lighter (P = 0.001) at 24 h. An interaction between scald time and sampling time showed in an increase in L* values at 4-min immediately following scald (P < 0.001). Two-hundred carcasses were then subjected to a modified scald time (6.5 min, or 7.5 min) in an industrial setting. Lowering scald time failed to recapitulate results. In fact, darker meat (L* value; P = 0.0166) was noted in the SM across longer scalds. These data suggest modest changes in scald time may not be responsible for changes in pork quality development.

Inherent factors influence color variations in semimembranosus muscle of pigs.

Variations in color, though a quality frustration, are common across the face of fresh and processed hams. Herein, we measured objective color across the semimembranosus (SM) muscle early postmortem and at 1440 min, then compared these differences against biochemical and metabolic characteristics responsible for pork quality development. Color (L*, a*) differed (P < 0.001) by zone and time but no interaction was evident. Lactate content and pH were highly correlated (R2 = 0.92) at 30 min, but weakened (R2 = 0.161412) by 1440 min. Lactate anaplerosis was not responsible for this lack of relationship. Glycolytic potential also differed across zone (P < 0.001) and time (P < 0.005). Differences in myoglobin expression and abundance, as well as mitochondrial DNA were notable (P < 0.05) across zone. These data suggest inherent differences in SM muscle are key determinants of ham color variation, while postmortem metabolism may play a lesser role in driving this quality attribute.

Muscle characteristics only partially explain color variations in fresh hams.

Fresh hams display significant lean color variation that persists through further processing and contributes to a less desirable cured product. In an attempt to understand the underlying cause of this color disparity, we evaluated the differences in muscle characteristics and energy metabolites across semimembranosus (SM) muscles differing in color variation. The L* (lightness) and a* (redness) values were highest and lowest (P<0.001), respectfully in the most caudal aspects of the muscle while the ultimate pH was the lowest (P<0.001). Correspondingly, this region possessed highest (P<0.01) glycolytic potential (GP) and lactate dehydrogenase (LDH) levels but did not differ in the amount of myoglobin or myosin heavy chain type I isoform. These data show that differences in muscle may contribute to ham color variation but suggest other factors may mitigate or exacerbate these variances.

Structural, magnetic, and Mössbauer spectral study of the electronic spin-state transition in [Fe{HC(3-Mepz)2(5-Mepz)}2](BF4)2.

The complex [Fe{HC(3-Mepz)(2)(5-Mepz)}(2)](BF(4))(2) (pz = pyrazolyl ring) has been prepared by the reaction of HC(3-Mepz)(2)(5-Mepz) with Fe(BF(4))(2) x 6 H(2)O. The solid state structures obtained at 294 and 150 K show a distorted iron(II) octahedral N(6) coordination environment with the largest deviations arising from the restrictions imposed by the chelate rings. At 294 K the complex is predominately high-spin with Fe-N bond distances averaging 2.14 A, distances that are somewhat shorter than expected for a purely high-spin iron(II) complex because of the presence of an admixture of about 80% high-spin and 20% low-spin iron(II). At 294 K the twisting of the pyrazolyl rings from the ideal C(3v) symmetry averages only 2.2 degrees, a much smaller twist than has been observed previously in similar complexes. At 150 K the Fe-N bond distances average 1.99 A, indicative of an almost fully low-spin iron(II) complex; the twist angle is only 1.3 degrees, as expected for a complex with these Fe-N bond distances. The magnetic properties show that the complex undergoes a gradual change from low-spin iron(II) below 85 K to high-spin iron(II) at 400 K. The 4.2 to 60 K Mössbauer spectra correspond to a fully low-spin iron(II) complex but, upon further warming above 85 K, the iron(II) begins to undergo spin-state relaxation between the low- and high-spin forms on the Mössbauer time scale. At 155 and 315 K the complex exhibits spin-state relaxation rates of 0.36 and 7.38 MHz, respectively, and an Arrhenius plot of the logarithm of the relaxation rate yields an activation energy of 670 +/- 40 cm(-1) for the spin-state relaxation.

Gender differences in disordered eating and its correlates.

The goal of this study was to examine gender differences in the prevalence of disordered eating and body dissatisfaction as well as examine gender differences in several risk factors: mass media, self-esteem and perfectionism. Three hundred fifty-three undergraduates completed surveys about their body dissatisfaction, disordered eating habits, exposure to and influence of mass media, self-esteem and perfectionistic tendencies. As expected, women experienced more symptoms of disordered eating as well as body dissatisfaction than did their male counterparts. There were also gender differences in the risk factors. For women, mass media, self-esteem, and perfectionism related to disordered eating behaviors, whereas for men, only perfectionism and mass media related to disordered eating behaviors. For women, mass media and self-esteem related to body image dissatisfaction, whereas for men, mass media and perfectionism related to body image dissatisfaction. The results of the present study indicate that risk factors for disordered eating and body dissatisfaction for men and women may be different, which has implications for understanding the etiology of body dissatisfaction and disordered eating and for possible treatment interventions.

Structure-function correlations in Iron(II) tris(pyrazolyl)borate spin-state crossover complexes.

Iron(II) poly(pyrazolyl)borate complexes have been investigated to determine the impact of substituent effects, intramolecular ligand distortions, and intermolecular supramolecular structures on the spin-state crossover (SCO) behavior. The molecular structure of Fe[HB(3,4,5-Me3pz)3]2 (pz = pyrazolyl ring), a complex known to remain high spin when the temperature is lowered, reveals that this complex has an intramolecular ring-twist distortion that is not observed in analogous complexes that do exhibit a SCO at low temperatures, thus indicating that this distortion greatly influences the properties of these complexes. The structure of Fe[B(3-(cy)Prpz)4]2.(CH3OH) ((cy)Pr = cyclopropyl ring) at 294 K has two independent molecules in the unit cell, both of which are high spin; only one of these high-spin iron(II) sites, the site with the lesser ring-twist distortion, is observed to be low-spin iron(II) in the 90 K structure. A careful evaluation of the supramolecular structures of these complexes and several similar complexes reported previously revealed no strong correlation between the supramolecular packing forces and their SCO behavior. Magnetic and Mössbauer spectral measurements on Fe[B(3-(cy)Prpz)4]2 and Fe[HB(3-(cy)Prpz)3]2 indicate that both complexes exhibit a partial SCO from fully high-spin iron(II) at higher temperatures, respectively, to a 50:50 high-spin/low-spin mixture of iron(II) below 100 K. These results may be understood, in the former case, by the differences in ring-twisting and, in the latter case, by a phase transition; in all complexes in which a phase transition is observed, this change dominates the SCO behavior. A comparison of the Mössbauer spectral properties of these two complexes and of Fe[HB(3-Mepz)3]2 with that of other complexes reveals correlations between the Mössbauer-effect isomer shift and the average Fe-N bond distance and between the quadrupole splitting and the average FeN-NB intraligand dihedral torsion angles and the distortion of the average N-Fe-N intraligand bond angles.

Directional control of pi-stacked building blocks for crystal engineering: the 1,8-naphthalimide synthon.

Incorporating the 1,8-naphthalimide group into bis(pyrazolyl)methane ligands triggers the association of their rhenium(i) complexes into directionally ordered dimers in both solution and solid state, as demonstrated by ES+/MS, PGSE-NMR and X-ray diffraction studies.

Dispersive perturbations of optical solitons.

The precise manner in which radiation disperses away from a soliton in an optical fiber is a topic attracting current attention. The purpose of this paper is to emphasize that there exists a well-developed formalism derived from inverse scattering theory, which has ready application to this problem for the case when the radiation in question forms part of the input pulse to the fiber.

Hodgkin's and non-Hodgkin's lymphoma: spectrum of morphologic and immunophenotypic overlap.

Immunoperoxidase markers are useful and often essential in distinguishing among lymphocyte-predominant Hodgkin's lymphoma, T-cell-rich B-cell lymphoma, and lymphocyte-rich classic Hodgkin's lymphoma. However, it is becoming increasingly clear that these "entities" are closely related clonal B-lineage neoplasms that may intertransform and/or coexist. We hypothesized that, just as there are cases with morphologic overlap, there would also be immunophenotypic overlap that would be found when a series of such cases is studied in detail. Eight cases of lymphocyte predominant Hodgkin's lymphoma, eight cases of lymphocyte-rich classic Hodgkin's lymphoma, seven cases of T-cell-rich B-cell lymphoma, and four cases of large B-cell lymphoma with focal features of T-cell-rich B-cell lymphoma were examined by the immunoperoxidase technique for expression of CD3, CD15, CD30, CD20, CD57, epithelial membrane antigen, and Epstein-Barr virus latent membrane protein (EBV LMP). All eight of the lymphocyte-predominant Hodgkin's lymphoma cases had CD20+ lymphocytic and histiocytic cells and CD57+ rosettes; however, in two cases, occasional lymphocytic and histiocytic cells were also weakly positive for CD15, CD30, and EBV LMP. Among the eight lymphocyte-rich classic Hodgkin's lymphoma cases, CD15+ Reed-Sternberg (R-S) cells were found in seven; however, in three of these cases rare rosettes of CD57+ cells surrounded the R-S or lacunar cells. In one case of large B-cell lymphoma the malignant cells resembled R-S cells and were CD20+, EBV LMP+, CD30+, CD15-, and surrounded by rosettes of CD57+ T cells. The majority of the cases exhibited the "expected" immunophenotypic patterns; however, the exceptional cases that were found serve to confirm the interrelationship among these clonal B-lineage neoplasms.

Incompatibility of polarization-division multiplexing with wavelength-division multiplexing in soliton-transmission systems.

In a recent experiment it was demonstrated that polarization-division multiplexing was incompatible with wavelength-division multiplexing. We discuss a theoretical model that explains this result.

Stochastic perturbations of optical solitons.

The problem of optical soliton propagation in the presence of a stochastic perturbation is considered. Two distinct types of stochasticity are distinguished, termed inhomogeneous and homogeneous. For the latter, the appropriate evolution equations for the soliton parameters (the amplitude eta and velocity K) are derived. These are shown to be of the multiplicative Langevin type and are then briefly discussed. Comparison is made with similar studies elsewhere.

Spectral modulation and the growth of resonant modes associated with periodically amplified solitons.

A first-order spectral perturbation theory of resonant modes that evolve with periodically amplified optical fiber solitons is presented. In contrast with the modulational instability, these modes exhibit a linear growth in amplitude with respect to propagation and have a tuning characteristic that follows an inverse square-root dependence on the amplification period. Numerical results based on a complete solution of the nonlinear Schrödinger equation are also presented that confirm and quantify this behavior.

Penetration and development of Meloidogyne hapla in resistant and susceptible alfalfa under differing temperatures.

Studies were conducted to examine under differing temperatures (12, 16, 20, 24, 28, and 32 C) the penetration anti development of Meloidogyne hapla in resistant lines '298' and 'Nev. Syn XX', and susceptible 'Lahontan' and 'Ranger' hardy-type alfalfas. The results indicated that resistance to M. hapla was similar to that previously described for M. incognita in nonhardy alfalfa. Although initial penetration in resistant seedlings was similar to that of susceptible seedlings, nematode larvae failed to establish and develop in root tissues and nematode numbers subsequently declined. In susceptible seedlings, nematode development proceeded rapidly, and egg production began after 5 weeks. Temperature had little influence on the nematode development except to slow the response at the lower temperatures. Other studies were conducted to verify a previously reported immune (no penetration) reaction to M. hapla by the 'Vernal' selection 'M-4'. When compared to the resistant (penetration without nematode development) Vernal selection 'M-9' under differing temperatures (20, 24, 28, and 32 C), each selection was equally penetrated by M. hapla but at a lower level than in susceptible Ranger cuttings. Generally, no root galling was observed in either M-4 or M-9; however, very slight galling was found 35 days after inoculation on about 50% of these cuttings when grown at 32 C.

Factors affecting the infection of alfalfa seedlings by Ditylenchus dipsaci.

Experiments were conducted to determine the effects of plant confinement, soil type, watering practices, stage of seed germination, inoculum level, and method of applying inoculum on stem nematode (Ditylenchus dipsaci) infection of alfalfa (Medicago sativa) seedlings grown in soil. Results indicated that (i) confining seedlings together with the nematodes in small vials offered no advantage over growing plants in large flats, (ii) a very fine sandy-loam soil was superior to a fine sand for stem-nematode penetration, (iii) nematodes penetrated seedlings more readily if the soil was not watered immediately after planting and inoculation, (iv) germinating seeds with a radicle length of 0.6-1.3 cm had the highest nematode penetration, and (v) highest penetration occurred when the nematodes were placed directly upon germinating seeds. The optimum inoculum level was 50 nematodes per seedling.

Mass Culturing of Ditylenchus dipsaci to Yield Large Quantities of Inoculum.

Methods are described for rearing large quantities of Ditylenchus dipsaci on alfalfa tissues. Nematodes and alfalfa seed were disinfected and nematodes were reared in quantities sufficient to provide a continuous supply of inoculum for our alfalfa-breeding program. Nematodes reproduced best in darkness at 20-25 C. Cultures reached maximum numbers in 3-6 wk.