Effect of housing system and feed restriction on meat quality of medium-growing chickens.

The aim of the study was to evaluate the differences in meat quality of 420 Hubbard JA757 cockerels in relation to the housing system (litter and mobile box) and level of mixed feed (ad libitum [AL], reducing the level by 20% [R20] and 30% [R30]). Three groups of chickens were housed in litter boxes for the entire fattening period (stocking density: 0.094 m2/bird). The other 3 groups were housed in litter boxes until 28 d of age and then relocated into mobile boxes (stocking density: 0.154 m2/bird) on pasture until the end of the experiment at 57 d of age. Restricted groups received a reduced diet level from 29th to 57th d of age. Feed mixture restriction increased the pasture vegetation intake of chickens from 2.63 to 3.50 (R20) and 3.94 g of dry matter/bird/d (R30). Restriction adversely affected the dressing percentage (P < 0.001) and breast yield (P < 0.001), while the leg yield (P < 0.001) was increased with increasing restriction levels. Meat of chickens housed in mobile boxes on a pasture showed lower cooking loss (P < 0.001) and higher redness and yellowness values in the skin (P = 0.030 and P = 0.026; respectively) and meat (P = 0.008 and P < 0.001; respectively). The fragile meat after cooking was observed in chickens reared on litter (P = 0.001). As the level of restriction increased, the number of muscle fibres (P = 0.001) increased, and their cross-sectional area (P = 0.001) and diameter (P = 0.002) decreased. The highest contents of lutein (P = 0.002) and zeaxanthin (P = 0.006) in breast muscle were found in chickens housed in mobile boxes and fed 80% and 70% AL. However, the concentrations of α- and γ-tocopherol (P = 0.006 and P = 0.003) were negatively affected by feed restriction. A 30% reduction in feed level in outdoor housed chickens led to a decrease in oxidative stability (P = 0.024). Feed restriction (R20) in chickens housed in mobile boxes significantly increased the n3 fatty acids content (P = 0.002) and h/H index (P = 0.005) and reduced the n6/n3 ratio (P < 0.001) and atherogenic (P < 0.001) and thrombogenic index (P = 0.003), which possess a health benefits for human. In addition, restriction of mixed feed decreased cholesterol content in breast meat (P = 0.042). It might be concluded that, in terms of meat quality, cereal diet restriction of 20% in medium-growing cockerels housed in mobile boxes on a pasture is beneficial. The higher level of restriction does not lead to further improvement in meat quality indicators.

Effects of pure plant secondary metabolites on methane production, rumen fermentation and rumen bacteria populations in vitro.

In this study, the effects of seven pure plant secondary metabolites (PSMs) on rumen fermentation, methane (CH4 ) production and rumen bacterial community composition were determined. Two in vitro trials were conducted. In trial 1, nine concentrations of 8-hydroxyquinoline, α-terpineol, camphor, bornyl acetate, α-pinene, thymoquinone and thymol were incubated on separate days using in vitro 24-hr batch incubations. All compounds tested demonstrated the ability to alter rumen fermentation parameters and decrease CH4 production. However, effective concentrations differed among individual PSMs. The lowest concentrations that reduced (p < .05) CH4 production were as follows: 8 mg/L of 8-hydroxyquinoline, 120 mg/L of thymoquinone, 240 mg/L of thymol and 480 mg/L of α-terpineol, camphor, bornyl acetate and α-pinene. These concentrations were selected for use in trial 2. In trial 2, PSMs were incubated in one run. Methane was decreased (p < .05) by all PSMs at selected concentrations. However, only 8-hydroxyquinoline, bornyl acetate and thymoquinone decreased (p < .05) CH4 relative to volatile fatty acids (VFAs). Based on denaturing gradient gel electrophoresis analysis, different PSMs changed the composition of bacterial communities to different extents. As revealed by Ion Torrent sequencing, the effects of PSMs on relative abundance were most pronounced in the predominant families, especially in Lachnospiraceae, Succinivibrionaceae, Prevotellaceae, unclassified Clostridiales and Ruminococcaceae. The CH4 production was correlated negatively (-.72; p < .05) with relative abundance of Succinivibrionaceae and positively with relative abundance of Ruminococcaceae (.86; p < .05). In summary, this study identified three pure PSMs (8hydroxyquinoline, bornyl acetate and thymoquinone) with potentially promising effects on rumen CH4 production. The PSMs tested in this study demonstrated considerable impact on rumen bacterial communities even at the lowest concentrations that decreased CH4 production. The findings from this study may help to elucidate how PSMs affect rumen bacterial fermentation.

In vitro Screening of Essential Oil Active Compounds for Manipulation of Rumen Fermentation and Methane Mitigation.

The objective of this study was to investigate the effects of 11 active compounds of essential oils (ACEO) on rumen fermentation characteristics and methane production. Two trials were conducted. In trial 1, ACEO (eugenol, carvacrol, citral, limonene, 1,4-cineole, p-cymene, linalool, bornyl acetate, α-pinene, and ß-pinene) at a dose of 1,000 µL/L were incubated for 24 h in diluted rumen fluid with a 70:30 forage:concentrate substrate (16.2% crude protein; 36.6% neutral detergent fiber). Three fistulated Holstein cows were used as donors of rumen fluid. The reduction in methane production was observed with nine ACEO (up to 86% reduction) compared with the control (p<0.05). Among these, only limonene, 1,4-cineole, bornyl acetate, and α-pinene did not inhibit volatile fatty acid (VFA) production, and only bornyl acetate produced less methane per mol of VFA compared with the control (p<0.05). In a subsequent trial, the effects on rumen fermentation and methane production of two concentrations (500 and 2,000 µL/L) of bornyl acetate, the most promising ACEO from the first trial, were evaluated using the same in vitro incubation method that was used in the first trial. In trial 2, monensin was used as a positive control. Both doses of bornyl acetate decreased (p<0.05) methane production and did not inhibit VFA production. Positive effects of bornyl acetate on methane and VFA production were more pronounced than the effects of monensin. These results confirm the ability of bornyl acetate to decrease methane production, which may help to improve the efficiency of energy use in the rumen.

Hybridization analysis and mapping of the celesticetin gene cluster revealed genes shared with lincomycin biosynthesis.

The first insight into celesticetin biosynthetic gene cluster of S. caelestis is presented. The genomic DNA of producing strain was digested, digoxigenin-labeled and hybridized with a set of probes designed according to S. lincolnensis gene sequences. Genes with high homology to the lincomycin biosynthetic genes coding for the predicted common parts of the pathway were identified in S. caelestis. Then, genomic DNA of S. caelestis treated by a multiple digestion was hybridized with five digoxigenin-labeled probes to construct a rough restriction map. Two consecutive islands formed by the genes with a putative function in biosynthesis of the shared saccharide moiety revealed an organization similar to the lincomycin biosynthetic gene cluster. The celesticetin cluster was mapped and essential information was obtained for subsequent steps, i.e. isolation and sequence analysis of the cluster.

Power Doppler dual-frame triggering of myocardial contrast echocardiography: a quantitative video intensity analysis.

AIM: The purpose of this study was to define the pattern of myocardial contrast observed during triggered dual-frame power Doppler imaging. METHODS AND RESULTS: Ten patients with no previous history of myocardial infarction underwent a continuous intravenous infusion of Optison at 0.5 ml/min. Triggered, sequential dual-frame power Doppler imaging was performed from an apical four-chamber view using a prototype Acuson Sequoia imaging system. The average triggering interval was once every four cardiac cycles, and the average interval between sequential frames was 50 msec. Video intensity analysis was performed in five myocardial regions of interest, and the percent decrease in video intensity of the destruction frames in each region of interest was determined by subtracting the destruction frame video intensity from the fill frame video intensity. The percent decrease in video intensity varied significantly by myocardial location (P < 0.001), with greater destruction seen in the apical than in the basal regions. CONCLUSION: This preliminary study demonstrates that power Doppler dual-frame triggering produces nonuniform decreases in video intensity, which likely represent nonuniform microbubble destruction. These results have important implications for the interpretation of myocardial perfusion patterns using this technique.

Long-term retention of transient news events.

Many retrospective analyses of remote memory have demonstrated recency effects in that memory for events proximal to the time of testing is superior to memory for events from remote time periods. However, the rate at which information decays over time and the specific pattern of forgetting may vary depending upon the distinct attributes of stimuli used as indices of memory. Studies examining long-term forgetting of well rehearsed, conceptually integrated information underscore preservation of remote events, some of which are thought to be permanently stored in memory. A different pattern of forgetting emerges in relation to recall of discrete facts whereby recall declines according to a negatively accelerated decay curve. In the current study long-term retention of transient news events was examined. Results were examined in relation to the effects of age and sex. All age groups demonstrated recency effects in that events from the recent past were recalled better than remote events. Age did not exert a negative influence on recall of remote or recent events with the exception of younger participants who did not recall items predating their dates of birth. Older female participants were less adept at recalling very old events than their male counterparts.

Role of perceptual and organizational factors in amnesics' recall of the Rey-Osterrieth complex figure: a comparison of three amnesic groups.

To examine the contribution of visual-perceptual and visual-organizational factors to visual memory in amnesia, Korsakoff, medial temporal, and anterior communicating artery (ACoA) aneurysm amnesics' copy, organization, and recall performance on the Rey-Osterrieth Complex Figure was assessed. Korsakoff patients were matched to medial temporal patients in terms of severity of amnesia, while the ACoA group, which was less severely amnesic, was matched to the Korsakoff patients on performance on executive tasks. Results indicated that while both the ACoA and Korsakoff groups had poorer copy accuracy and organization than controls, only the Korsakoff patients' copy accuracy was worse than the other two amnesic groups. While the Korsakoff patient's visuoperceptual deficits could partially explain this group's poor performance at immediate recall, the Korsakoff group's comparatively worse performance at delayed recall could not be accounted for by poor copy accuracy, reduced visual organization, or even the combined influence of these two factors.

Perceptual fluency as a cue for recognition judgments in amnesia.

This study investigated the extent to which amnesic patients use fluency of perceptual identification as a cue for recognition. Perceptual fluency was measured by having participants gradually unmask words before making recognition judgments. In Experiment 1, familiarity was the only possible basis for recognition because no words had been presented in the study phase. In Experiment 2, recollection provided an alternative basis for recognition because words had appeared in the study phase. Amnesic patients were as likely as normal controls to use perceptual fluency as a cue for recognition in Experiment 1 but were more likely than controls to do so in Experiment 2. For both groups, perceptual fluency affected judgments for studied and unstudied items to the same extent in Experiment 2. These findings suggest that amnesic patients do use perceptual fluency cues, but reliance on perceptual fluency does not necessarily elevate recognition accuracy.

The effects of divided attention during encoding and retrieval on amnesic patients' memory performance.

This study examined the effect of divided attention during encoding or retrieval on primary (recall) or secondary (button-pressing) task performance by amnesic patients and control subjects. Experiment 1 demonstrated that control subjects' recall was affected by divided attention during encoding but not during retrieval, while the amnesic patients' recall remained at the same low level for all conditions. Both groups showed a reduction in rate of button-pressing during encoding relative to their baseline levels and a further reduction during the retrieval interval. In Experiment 2, five learning trials, instead of just one, were presented. This acted to increase all subjects' recall and also had the effect of producing superior recall following free encoding relative to encoding during divided attention for the amnesic patients as well as for the control subjects. Button-pressing performance during the encoding interval increased to baseline for both groups during the five presentation trials, but there was no increase in the rate of button-pressing during the retrieval interval. Amnesic patients' normal attention to the primary task during encoding and retrieval was felt to have several implications for future neuroimaging tasks with these patients.

Intact temporal memory in amnesic patients.

Current theories propose that amnesia is caused by an inability to encode the temporal properties of recent events and/or to associate information across time. The present investigation tested this postulation by manipulating the recency effect which is theorized to be caused by the encoding of temporal information. The continual-distractor paradigm was used to vary the temporal properties of recently presented lists. Amnesics' recall responded normally to the temporal manipulations in lists ranging from 18-54 s. In contrast, overall recall was impaired compared to normals in all conditions and across all positions, including the final position. These findings dissociate memory for temporal information from overall levels of recall. They suggest that the amnesic patient's memory deficit is not caused by an inability to encode temporally associated information.

Effects of spacing and repetition on amnesic patients' performance during perceptual identification, stem completion, and category exemplar production.

The effects of repetition and spacing of repetitions on amnesic patients' implicit task performance was studied. Amnesic patients and control participants performed a perceptual identification task, a word-stem completion task, and a category exemplar production task after the presentation of target words repeated within a list. Repetition proved to have no effect on perceptual identification or on word-stem completion, but it did play a role in category exemplar production. As expected, the amnesic patients demonstrated normal performance on the perceptual identification and word-stem completion tasks. However, on category exemplar production, the amnesic patients' performance was significantly below that of the control participants, and the 2 groups differentially responded to repetition. The normal control participants' spontaneous ability to analyze semantic features of words led to unconscious priming of the category and its links to the exemplars after only one presentation of a word. Amnesic patients, on the other hand, seemed to rely more on the fluency produced by multiple presentations.

Amnesic patients' impaired category exemplar production priming.

This study examined the effect of varying the number of potential target words on amnesic patients' category exemplar production performance. In Experiment 1, 4 words from each of 6 categories were presented to amnesic patients and normal control participants. This was followed by an indirect task in which each participant produced the first 8 words that came to mind when presented with a category cue. On this task the amnesic patients were impaired. This outcome stands in sharp contrast to most other category exemplar production tasks that have been reported. However, these other paradigms tend to restrict participants' processing during target item presentation while our procedure allowed them to analyze the target words as they chose. Our procedure may have allowed the control participant more opportunity to "cluster" target words from the same category during list presentation and this, in turn, may have given them an advantage at the time of category exemplar production. Therefore, in Experiment 2, only 1 word per category was presented in the target list and only 2 words per category were requested during category exemplar production. Surprisingly, the amnesic patients still exhibited impaired performance. Therefore, it was suggested that perhaps amnesic patients' known inability to perform semantic levels of processing during individual target word presentation may have resulted in impaired priming for categorical features for these patients.

MMPI/MMPI-2: comparisons of amnesic patients.

The amnesic population provides a unique opportunity to examine the reliability of clinical tests because amnesics do not consciously recollect initial testing sessions. In this study, amnesic subjects were studied to examine the reliability between the Minnesota Multiphasic Personality Inventory (MMPI) and the MMPI-2. Findings indicated that there were no statistical differences between versions of the MMPI and further revealed that many of the scales were significantly correlated. Amnesic patients produced elevated scores on subscales two (depression) and eight (schizophrenia), not unlike various other groups of neurologically impaired individuals. This indicates that MMPI and MMPI-2 scores in these patient populations may reflect the medical and psychosocial effects of brain damage rather than premorbid personality dysfunction. A close evaluation of amnesics' performance, in conjunction with the critical items they endorsed, offers insight into the personality traits of the amnesic patient population. The relative stability of performance across personality tests administered over several weeks is relevant to the formation and stability of the amnesic's concept of self.

Unconscious influences on amnesics' word-stem completion.

Amnesic patients and control subjects were asked to complete three-letter word-stems under one of three retrieval conditions. In a direct condition, they were told to use the stems as retrieval cues for words that had just been presented in a study list. In an indirect condition, they were told to use the first word that came to mind with no reference made to the study list. Finally, in an oppositional condition, they were told to use the first word that came to mind unless it had appeared on the study list. During the study list presentation, the patients and controls had analyzed each word according to either semantic (associating to each word) or graphemic (counting letters with enclosed spaces) instructions. The results revealed that the control subjects produced a different number of study words during retrieval as a function of retrieval instructions and encoding condition. The amnesics, however, did not vary their performance as a function of retrieval instructions. Under all conditions, they completed the word-stems far more frequently with words from the study list than would be expected by chance and they consistently produced more semantic than graphemic responses. We concluded that semantic analysis might affect the fluency with which an item occurs for the amnesic, but that the item itself remains independent of the source of that fluency for these patients. Thus, the level of analysis performed on a word during study can affect the unconscious performance of amnesic patients but is unavailable for use during conscious retrieval.

A positive approach to viewing processing deficit theories of amnesia.

This reply is admittedly a defence of the encoding-deficits theory of amnesia. However, it attempts to go further by proposing that this deficit, which was originally designed just to explain amnesics' explicit episodic memory disorder, might be viewed as being but one instance of a more general disorder characteristic of all aspects of amnesic patients' information processing. It is proposed that amnesic patients' inability to perform more consciously controlled conceptual analyses results not only in explicit recall deficits, but sometimes also in instances of below normal implicit memory and recognition ability. Their ability to perform automatic, perceptual-level processing produces normal performance on some implicit and some recognition tasks, but it is not sufficient for all tasks.

Comparison of figural intrusion errors in three amnesic subgroups.

To examine the contribution of memory deficits and executive dysfunction to the production of prior-item intrusion errors, Korsakoff, mesial temporal amnesic, and anterior communicating artery aneurysm (ACoA) patients' performance on the Visual Reproduction subtest of the Wechsler Memory Scale-Revised (WMS-R) was assessed. The Korsakoff patients were matched to the mesial temporal group in terms of severity of amnesia, while the ACoA group, which was less severely amnesic, was matched to the Korsakoff group in their performance on executive tests. Results indicated that at immediate recall, Korsakoff patients made significantly more intrusions than mesial temporal and ACoA patients. Conversely, after a delay, ACoA patients tended to make more intrusions than the other groups. Findings suggest that intrusions are due to a combination of deficient memory and executive dysfunction. A further comparison of a subgroup of ACoA patients matched to the Korsakoff patients in terms of severity of amnesia, however, revealed differences in the pattern of intrusions of these two groups, suggesting that different mechanisms may underlie Korsakoff and ACoA patients' susceptibility to interference.

Impaired delay eyeblink conditioning in amnesic Korsakoff's patients and recovered alcoholics.

The performance of amnesic Korsakoff patients in delay eyeblink classical conditioning was compared with that of recovered chronic alcoholic subjects and healthy normal control subjects. Normal control subjects exhibited acquisition of conditioned responses (CRs) to a previously neutral, conditioned tone stimulus (CS) following repeated pairings with an unconditioned air-puff stimulus, and demonstrated extinction of CRs when the CS was subsequently presented alone. Both amnesic Korsakoff patients and recovered chronic alcoholic subjects demonstrated an impairment in their ability to acquire CRs. These results indicate that the preservation of delay eyeblink conditioning in amnesia must depend on the underlying neuropathology of the amnesic syndrome. It is known that patients with amnesia caused by medial temporal lobe pathology have preserved conditioning. We have now demonstrated that patients with amnesia caused by Korsakoff's syndrome, as well as recovered chronic alcoholic subjects, have impaired conditioning. This impairment is most likely caused by cerebellar deterioration resulting from years of alcohol abuse.

Intact delay-eyeblink classical conditioning in amnesia.

The status of classical conditioning in human amnesia was examined by comparing conditioning of the eyeblink response (the unconditional response) to a tone conditioned stimulus (CS) paired with an airpuff unconditioned stimulus (US) in the delay paradigm between 7 amnesic and 7 age- and education-matched normal control participants. Amnesic patients exhibited normal baseline performance in pseudoconditioning and normal acquisition and extinction of conditioned responses in terms of the number, latency, and magnitude of eyeblinks. These results indicate that in humans, as in rabbits, brain structures critical for declarative memory are not essential for the acquisition of elementary CS-US associations.

Acquisition of generic memory in amnesia.

Amnesic patients' ability to acquire generic, semantic information was assessed relative to their own level of episodic memory. Patients studied a list of words in which some items were presented twice and others once. Upon each presentation, the words were tagged episodically by presenting them in a unique color. Recall of the colors in which words were presented suggested that individual presentations of repeated items were less likely to be recalled than presentations of nonrepeated items; however, actual recall of repeated items exceeded that of nonrepeated items. This outcome demonstrated that amnesics can recall some items generically without recalling either of their individual presentations. However, amnesics' recall of twice-presented items remained far below that of the control group, even when their recall of once-presented items was matched by testing the control group after a delay. This finding suggests that amnesic patients can acquire new generic knowledge but do so much less efficiently than do normal individuals. Furthermore, this deficit occurs independently of the amnesics' episodic memory impairments, reflecting instead a disruption in semantic learning per se.

Episodic effects on picture identification for alcoholic Korsakoff patients.

Experience with degraded pictures produces better subsequent identification of these pictures in amnesic patients. To examine the contribution of episodic memory to this facilitation, we compared identification of pictures that were identical to a studied picture, pictures that shared the same name with a studied picture, and new, unstudied pictures. In an initial phase of the experiment, patients clarified each picture until they could name it. During a second phase, they again clarified each picture and judged whether it was identical, similar (same-name), or different from pictures identified in the first phase. Korsakoff patients, as well as alcoholic controls, identified identical pictures faster than same-name pictures, and these in turn were identified faster than new pictures. The Korsakoff patients did show less facilitation than the alcoholic controls, but this difference was eliminated by testing the alcoholics after a week delay. The smaller facilitation in performance shown by amnesics and by alcoholics tested after a delay was accompanied by impaired recognition memory as well as by qualitative differences in recognition performance. The Korsakoff patients tended to label same-name pictures as different while alcoholic controls tested immediately called them identical, a tendency which disappeared when alcoholics were tested after a delay. These findings suggest that Korsakoff patients are influenced by specific episodic information even more than are alcoholic controls.