Quantum-mechanical wavepacket transport in quantum cascade laser structures

We present a viewpoint of the transport process in quantum cascade laser structures in which spatial transport of charge through the structure is a property of coherent quantum-mechanical wavefunctions. In contrast, scattering processes redistribute particles in energy and momentum but do not directly cause spatial motion of charge.Comment: 6 pages, 5 figures included in tex, to appear in Physical Review

A spectroscopic method of temperature measurement which does not require transition probabilities

Spectroscopic method of temperature and pressure measurement in a plasma by comparing intensity ratios of spectral line

An Examination of Discrimination on Stress, Depression, and Oppression-Based Trauma During the COVID-19 Pandemic and the Racial Awakening of 2020

Background Discrimination is a pervasive societal issue that monumentally impacts people of color (POC). Many Black, Asian, and Hispanic/Latinx individuals report experiencing race-based discrimination in their lifetime. Discrimination has previously been linked to adverse health outcomes among POC, including stress, depressive, and posttraumatic stress disorder symptoms. These health disparities are posited to have become exacerbated by COVID-19 and the racial awakening of 2020. The current study examined the short- and long-term effects of discrimination on stress, depression, and oppression-based trauma among POC. Methods Participants were (n = 398) who identified as Black, Indigenous, Hispanic/Latinx, and Asian completed an online self-report survey assessing discrimination, depression, stress, and oppression-based trauma collected at 3 time points: (T1) beginning of the COVID-19 pandemic (May 2020), (T2) 6 weeks later during the racial awakening of 2020 (June 2020), (T3) one year later (June 2021). Results Significant positive paths were revealed from T1 discrimination to T2 depression, T2 stress, and T3 oppression-based trauma. The association between T1 discrimination and T3 oppression-based trauma was partially mediated by T2 depression, but not by stress; total and total indirect effects remained significant. The final model accounted for a significant proportion of the variance in T3 oppression-based trauma, T2 depression, and T2 stress. Conclusion Findings are consistent with prior research linking discriminatory experiences with mental health symptomatology and provide evidence that race-based discrimination poses harmful short-and long-term mental health consequences. Further research is necessary to better understand oppression-based trauma to improve the accuracy of clinical diagnosis and treatment of POC

Evaluation of Beef Steak Flavor Development in Vacuum Rollstock Packaging Under Two Lighting Sources

The objective of this study was to determine the influence of lighting type and display duration on flavor development in multiple beef muscles. Paired beef top sirloin butts, strip loins, and tenderloins were collected from USDA Low Choice carcasses (Small00 to Small100 marbling score, n=16). Subprimals were wet aged in the absence of light for 7 d postmortem at 0°C to 4°C before being fabricated into 2.5-cm steaks representing the Gluteus medius, Longissimus lumborum (LL), and Psoas major. Steaks were packaged individually in vacuum rollstock packaging and assigned to either light-emitting diode (LED) or fluorescent (FLUR) display cases for a display period of 0, 2, 6, or 10 d. All steaks were assigned to either trained descriptive panel analysis (n=384) or volatile compound analysis (n=384) and cooked to a medium degree of doneness (71°C). Two-way interactions occurred between lighting type and display duration, showing increased tenderness sooner during display for LED steaks, and lower umami intensity in FLUR steaks after 10 d (P<0.001). Lighting and muscle type showed more tender LL and Psoas major steaks in LED lighting (P≤0.001). Lighting and display duration interactions also showed increased concentrations of 2,3-butanedione under FLUR light and ethyl benzene under LED display (P≤0.043), whereas lighting and muscle type showed greater concentrations of alcohols and carboxylic acids in LL steaks under LED lighting (P≤0.046). Furthermore, discriminant function analyses were per-formed, suggesting that the most successful retail display period was within 2 to 6 d, with no difference between lighting types (P=0.212). Overall, these data reveal little differentiation between lighting types, implying that newer LED lighting does not detrimentally influence beef quality when vacuum packaging is utilized

Simultaneous ultrafast probing of intramolecular vibrations and photoinduced charge carriers in rubrene using broadband time-domain THz spectroscopy

Mattijs Koeberg, Euan Hendry, Juleon M. Schins, Hendrik A. van Laarhoven, Cees F. J. Flipse, Klaus Reimann, Michael Woerner, Thomas Elsaesser, and Mischa Bonn, Physical Review B, Vol. 75, article 195216 (2007). "Copyright © 2007 by the American Physical Society."We determine the ultrafast frequency- and time-resolved complex dielectric responses of photoexcited, single-crystal rubrene in the frequency range of 10–30 THz (330–1000 cm−1) using ultrafast broadband THz spectroscopy. In this frequency range, we observe the response of both photogenerated mobile charges and intramolecular vibrational modes simultaneously, both of which vary with time after excitation. The data in conjunction with a theoretical model indicate a dynamic blueshift of the 15.5 THz phonon

Flavor Development of Individually Vacuum-Packaged Beef Steaks During Extended Wet Aging

The objective of the study was to determine the effect of extended aging on the flavor development of various muscles, individually stored in vacuum rollstock packaging. Strip loins, paired tenderloins, and top sirloin butts (n=48) from USDA Low Choice carcasses (Small00 to Small100 marbling score, n=16). Subprimals were wet-aged in the absence of light for 28 d postmortem before fabrication into 2.54 cm steaks representing the longissimus lumborum (LL), psoas major (PM), and gluteus medius (GM). Steaks were individually packaged in vacuum rollstock packaging and assigned to an additional aging time of 28, 35, 42, 49, or 56 d. Cut steaks (n=240/test) were designated to trained descriptive panel analysis or volatile compound analysis. No interactions occurred for trained sensory analysis, but a main effect of days of age (P≤0.033) showed the greatest effect on negatively associated attributes, including liver-like, oxidized, fishy, bitter, and sour, after 42 d of aging. A main effect of muscle type also occurred (P≤0.040) for flavor attributes, in which GM and PM samples scored higher in off-flavor attributes compared with LL samples, including flavors such as liver-like, oxidized, and sour. An interaction between muscle type and days of age occurred for 2-pentyl-furan (P=0.021). One compound—3 hydroxy-2 butanone—was affected by muscle type (P=0.009). However, most compounds were affected by days of age (P≤0.046), in which compounds related to off-flavors increased in concentrations the most after 49 d. Additionally, discriminant function analyses were performed, suggesting the most effective aging time for individual steaks to be under 49 d when considering loadings for volatile compounds and flavor attributes corresponding with days of age. Overall, these data suggest individual packaging of GM, LL, and PM muscles is most optimal for up to 42 or49 d of age without a large impact from the presence of off-flavors, thus providing food service establishments the opportunity to individually package beef steaks for an extended period while maintaining consumer satisfaction through optimal flavor

Effect of Extended Postmortem Aging on Beef Muscles of Differing Quality Grade during Retail Display

Aging of beef subprimals is a common industry practice to improve tenderness. However, the effect of extended aging (up to 63 d) on retail shelf life, tenderness, and eating quality of beef strip loin and sirloin of differing quality grades is not clearly understood. Therefore, in the current study, longissimus dorsi (strip loin) and gluteus medius muscles (sirloin) were collected from USDA Choice or Select carcasses and fabricated into 6 portions. Each of these portions was designated to an assigned time of wet aging (14, 21, 28, 35, 45, or 63 d) in vacuum bags. After aging, samples were fabricated into steaks and placed into a multideck retail display case for 72 h. Steaks were evaluated for color (instrumental and color panelists) every 8 h during retail display, and Warner-Bratzler shear force and sensory analysis were conducted after retail display. The results were analyzed using the PROC MIXED procedure of SAS with repeated measures for the color data. Among the effects evaluated (aging, quality grade, and aging×quality grade), quality grade was not significant (P>0.05) for either strip loin or sirloin steaks. An aging×display hour interaction was identified (P<0.05) for the color measurements. In general, as aging time increased over the display period, color was negatively impacted. Although tenderness improved (P<0.05) with aging, the incidence of off-flavors also increased, especially in sirloin steaks, suggesting that beef processors need to consider flavor changes during extended aging

The Impact of Carcass Size, Chilling Conditions, and Electrical Stimulation on Beef Postmortem Temperature and pH Decline

Variability in carcass size can influence carcass chilling rates, which could result in issues associated with beef tenderness and color. Moreover, the usage of electrical stimulation can affect postmortem metabolism and meat quality. However, few studies have looked at the combined impact of chilling and electrical stimulation on temperature decline, postmortem biochemistry, and color among the current population of US beef. Beef carcasses (N = 162, < 30 mo) were randomly selected from 2 beef processing plants. One side of each carcass was electrically stimulated, while the opposing side was not electrically stimulated. Matched sides were subjected to either conventional spray chilling (CONV) or delayed spray chilling (DELAY). Deep tissue (10.5 cm under the pelvic bone) and surface temperature (1.5 cm under the loin fat) were continuously monitored during chilling in addition to temperature and pH measurements from the semimembranosus (SM), longissimus lumborum (LL), and psoas major (PM) muscles at an initial time (45 to 60 min), 6 h, 12 h, and after chilling (28 to 36 h) postmortem. Further, the instrumental (L*, a*, and b*) and visual color were evaluated on 14-d aged PM steaks. For data analysis, carcasses with hot carcass weights above or below the plant average were considered heavy or light, respectively. A nonlinear regression model was fitted to the continuous deep and surface temperatures, whereas other parameters were evaluated using a mixed model. Electrical stimulation improved L* (lightness; P < 0.05) of PM in light- weight carcasses but not (P > 0.05) in heavyweight carcasses. Temperature decline was faster (P < 0.05) and pH decline slower (P < 0.05) in the SM and LL of lightweight carcasses under CONV compared to lightweight carcasses under DELAY and heavyweight carcasses under CONV and DELAY. Exponential decay models for deep and surface temperatures indicated the rate of cooling differed (P < 0.05) due to the combination of treatment factors. Heavyweight carcasses in DELAY had slower rates of temperature decline (P < 0.05). Overall, the variability in carcass size affected temperature decline and postmortem metabolism. Therefore, postmortem management practices should consider carcass weights to optimize meat quality

The Psychosocial Health of Shan Children in Northwest Thailand

We administered the Strengths and Difficulties Questionnaire (SDQ) to 51 Shan refugee children from Burma who are living in northern Thailand, and collected life histories from 11 of their families. Of the sample, 63% of the children were stateless, and none were Thai citizens. About 30% of the children had normal peer relationship subscores—a number well below Thai norms after correcting for multiple comparisons (p < .001). However, their overall functioning was not different from the Thai population as a whole

Absent in Melanoma 2 (AIM2) is an important mediator of interferon-dependent and -independent HLA-DRA and HLA-DRB gene expression in colorectal cancers

Absent in Melanoma 2 (AIM2) is a member of the HIN-200 family of hematopoietic, IFN-inducible, nuclear proteins, associated with both, infection defense and tumor pathology. Recently, AIM2 was found to act as a DNA sensor in innate immunity. In addition, we and others have previously demonstrated a high frequency of AIM2-alterations in microsatellite unstable (MSI-H) tumors. To further elucidate AIM2 function in colorectal tumors, we here addressed AIM2-responsive target genes by microarray based gene expression profiling of 22 244 human genes. A total of 111 transcripts were significantly upregulated, whereas 80 transcripts turned out to be significantly downregulated in HCT116 cells, constitutively expressing AIM2, compared with AIM2-negative cells. Among the upregulated genes that were validated by quantitative PCR and western blotting we recognized several interferon-stimulated genes (ISGs: IFIT1, IFIT2, IFIT3, IFI6, IRF7, ISG15, HLA-DRA, HLA-DRB, TLR3 and CIITA), as well as genes involved in intercellular adhesion and matrix remodeling. Expression of ISGs correlated with expression of AIM2 in 10 different IFN-γ treated colorectal cancer cell lines. Moreover, small interfering RNA-mediated knock-down of AIM2 resulted in reduced expression of HLA-DRA, HLA-DRB and CIITA in IFN-γ-treated cells. IFN-γ independent induction of HLA-DR genes and their encoded proteins was also demonstrated upon doxycyclin-regulated transient induction of AIM2. Luciferase reporter assays revealed induction of the HLA-DR promoter upon AIM2 transfection in different cell lines. STAT-signaling was not involved in IFN-γ independent induction of ISGs, arguing against participation of cytokines released in an autostimulating manner. Our data indicate that AIM2 mediates both IFN-γ dependent and independent induction of several ISGs, including genes encoding the major histocompatibility complex (MHC) class II antigens HLA-DR-α and -β. This suggests a novel role of the IFN/AIM2/ISG cascade likewise in cancer cells