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Valorisation of spent coffee grounds in the context of prebiotic potential: a review
Get PDFSpent coffee grounds (SCGs) are the solid residues generated after coffee brewing and have been widely researched due to their rich carbohydrate content. Beyond energy generation, there is a growing interest in developing functional food ingredients. This review focuses on assessing various extraction methods for SCG-derived compounds in terms of their prebiotic potential.
One common type of functional carbohydrate extracted from SCGs is mannooligosaccharides (MOS), primarily obtained through single-stage and enhanced extraction strategy. Single-stage extraction often uses one method, with integrated mechanism and yields oligosaccharides and monosaccharides. On the other hand, the enhanced extraction combines pre-treatments and enzymatic hydrolysis to increase the SCG extractability and selectively degrade polysaccharides. This method yields fewer undesired by-products and aims to avoid complete hydrolysis of SCG into monosaccharides.
In this review, several research gaps were identified in relation to fully valorise SCG. First, there is a critical gap in standardized analytical methods for accurately determining the profile of extracted oligosaccharides. Developing and adopting validated techniques is essential for a reliable characterization of these compounds. Second, the efficacy of pretreatment processes on SCG remains challenging to assess due to the lack of uniform evaluation criteria. Establishing such criteria would help compare across studies, ensuring more consistent assessment of pretreatment outcomes. Finally, the criteria for confirming prebiotic potential in SCG-derived compounds are not well understood. It is essential to adhere to established definitions of the term ‘prebiotic’ and to apply validated methodologies to assess their prebiotic status
Anaerobic digestion of whey permeate: exploring operational parameters, supplementation strategies, and microbial dynamics for enhanced methane production methane production
No full textThe increasing demand for whey protein products has led to significant production of whey
permeate as the byproduct. Whey permeate has a high organic load, mainly due to high
lactose concentration with small amount of other organic compounds, which limits its
potential applications. The high organic load of whey permeate poses environmental risks if
directly discharged without prior treatments. Thus, effective treatment strategies for whey
permeate become important to support the growth and circularity within the dairy industry.
The current applications of whey permeate have been facing various challenges, such as
limited consumer acceptance when used as consumable products — especially for
consumers with lactose intolerance, handling difficulties due to lactose crystallization, as
well as secondary waste generation and needing complex processes that further adds to the
cost of treating the byproduct. By considering these challenges, anaerobic digestion (AD)
emerges as a promising solution for whey permeate treatment. The AD technology offers
practicality and versatility in processing diverse feedstocks to produce renewable energy in
the form of methane (CH4) gas and valuable byproducts like volatile fatty acids (VFAs).
Furthermore, the AD process simultaneously reduce organic load of the digested feedstock
with minimum secondary waste generation. This study investigates optimization strategies
for AD of whey permeate to enhance CH4 production by initially observed whey permeate
potential as an AD feedstock under batch reactors. Subsequently, optimization strategies for
whey permeate AD were explored under semi-continuous stirred tank reactor (s-CSTR)
system, which include the application of different organic loading rate (OLR), digestate
recirculation, activated carbon (AC) supplementation, as well as organic (urea) and
inorganic (ammonium sulfate) nitrogen supplementation.
Initial investigations into AD of whey permeate were conducted through biochemical
methane potential (BMP) tests by evaluating the effect of inoculum-to-substrate ratios
(ISRs), pH levels, and temperatures under batch reactors. The highest CH4 production has
iii
shown to be achieved at different temperatures when different source of whey permeate were
used. In our first BMP test using liquid whey permeate, optimal conditions were achieved at
an ISR of 2, pH 8, and 30 °C. This operational condition resulted with a cumulative CH4
yield of 466.29 ± 13.71 NLCH4.kgVS⁻¹. However, when powdered whey permeate from a
different source was tested, the optimal operation shifted to ISR of 2, pH 7.5, and 37 °C,
which produced a higher cumulative CH4 production of 653.64 ± 12.16 NLCH4.kgVS⁻¹.
Furthermore, directly applying kinetic parameters as determined from the BMP tests data
into s-CSTR system revealed operational challenges. Despite achieving a high CH4 yield in
batch systems under ISR 2 with technical digestion time (T80-90) of 14 d, applying these
parameters to determine the OLR and hydraulic retention time (HRT) values for s-CSTR
system resulted with operational instability and ultimately system failure. In response to this,
kinetic parameters from BMP tests were only used as rough guidelines. The observation of
whey permeate AD under s-CSTR system was then operated at OLR of 2.5 and 4 gVSL
-1d
-1
with HRT of 30 d for 150 days. In this operational set up, CH4 production rate was declining
for the first three HRTs before stabilizing for the rest of the observation. This study revealed
that OLR of 2.5 gVSL
-1d
-1 produced higher cumulative CH4, with the average daily CH4
production of 38.20 ± 5.04 NLCH4kgVS⁻¹d
-1 during steady period. The decline in CH4
production during the first three HRTs, as well as different AD performance between each
observed reactors, were shown to be correlated with volatile solids degradation, VFA
accumulation, and shifts in microbial communities. Initially, acetogenic bacteria (e.g.,
Trichococcus and Sedimentibacter) dominated the digestate, but over time, propionic acid-producing bacteria (e.g., Actinomyces and Acidipropionibacterium) became prevalent.
Concurrently, the dominant archaea in the digestate shifted from Methanosarcina to
Methanobacterium, indicating a transition in methanogenesis pathways that directly
impacted AD performance.
iv
Following results from different OLRs experiment, AC supplementation and digestate
recirculation alongside trace elements addition were investigated at OLR of 2.5 gVSL
-1d
-1 to
further explore strategies for AD optimization. In this experiment, stable CH4 productions
were observed in all reactors since the first HRT. This indicates that trace elements addition
at the concentration of 0.3 ppm could stabilize CH4 production in whey permeate AD.
Moreover, combining one-time AC supplementation with digestate recirculation
significantly improved CH4 yields, with the daily average of 60.53 ± 13.72 NLCH4kgVS⁻¹d
-1
.
This CH4 yield outperforms reactors with daily AC supplementation or digestate
recirculation alone. These interventions also influenced microbial communities, where
Methanosarcina and Methanoculleus populations were enriched. Separately, this study also
investigates nitrogen and AC supplementation strategies towards AD of whey permeate.
Two different nitrogen sources, urea (organic nitrogen source) at the concentration of 0.07
g.L-1
and ammonium sulfate (inorganic nitrogen source) at the concentration of 0.16 g.L-1
are supplemented separately to fix the C/N ratio of the system into 25. The effects of the
nitrogen alongside AC supplementation on AD performance of whey permeate are then
evaluated. This investigation reveals that nitrogen alongside AC supplementation increased
CH4 production, with the average increase at 7–42% as compared to reactor without nitrogen
supplementation. Furthermore, urea supplementation alone achieved the highest CH4 yield
at the average daily production of 81.73 ± 20.32 NLCH4kgVS⁻¹d
-1
. Similar to the different
OLRs experiment, microbial analysis indicated a transition from Methanosarcina to
hydrogenotrophic methanogens like Methanobacterium and Methanoculleus, suggesting
that digestate recirculation had an effect to maintain acetoclastic methanogens population,
while nitrogen supplementation promotes hydrogenotrophic methanogens, regardless of AC
supplementation.
In summary, while AD presents a viable pathway for whey permeate valorization, achieving
stable and efficient operations requires careful optimization of parameters such as ISR, pH,
temperature, and nutrient balance. Strategies like AC supplementation, digestate
recirculation, and nitrogen management offer promising avenues for enhancing AD
performance and microbial stability. Further research is needed to address scalability, and
long-term operational challenges, paving the way for sustainable and economically feasible
whey permeate utilization
Team decision-making through English as a medium of professional medical communication in doctor-doctor meetings in a Saudi hospital: a multimethod discourse approach
Get PDFThis study addresses the gap in understanding decision-making (DM) as a distinct interactional
genre within multilingual and multicultural healthcare teams such as those increasingly prevalent
in Saudi Arabia. While previous discourse-analytical research has focused primarily on DM in
doctor-patient interactions, little is known about how decisions are made interactively in doctor-doctor communication, particularly in settings where English is the medium of professional
medical communication (PMC). Effective DM is crucial in medical contexts, as
miscommunication can have serious consequences for patient outcomes. This study empirically
explores the language and discursive resources used by doctors in team DM, offering insights for
both practicing and future medical professionals. It also provides pedagogical implications for
improving English medical education in Saudi Arabia, where current research often critiques the
English proficiency of medical graduates without specifying the practical needs of the workplace.
A multimethod discourse approach has been adopted in this study to systematically investigate
and answer the research questions. The combination includes the following qualitative methods:
Genre Analysis (GA), Conversation Analysis (CA), and Interactional Sociolinguistics (IS). No
existing studies in the DM literature have used this kind of multimethod discourse approach to
explore decision-making as an ongoing, moment-by-moment process in doctor-doctor team
meetings. The primary data in this study are weekly doctor-doctor meetings, during which critical
decisions are made. The analysis of the transcribed data started with GA to identify patterns –
Moves and Steps – characterizing DM as an interactional genre in a multilingual medical setting.
Subsequently, CA was employed to examine the turns within the moves and provided deeper
insights into how doctors managed their linguistic and other verbal resources during the DM
interactions – most notably code-switching and humour – which emerged as prominent discursive
features of the studied doctor-doctor communication. Drawing on IS allowed for the consideration
of factors beyond the conversational data, specifically the doctors’ epistemic status and primacy,
which contextualised the analysis within the medical setting and its professional hierarchy.
The findings that emerged from the GA provided generic features of medical decision-making
episodes, where one type was unambiguous and straightforward and less frequent, while the other
was more complex and occurred more frequently. Both types of decisions share basic Moves that
include Presenting the patient, Pre-decision, Decision, and Closing. However, complex decisions
had more variability, as the discussions were more extended and included Moves such as Decision
execution details and Re-discussing the medical status of the patients. Both unambiguous and
complex decisions depended on collective agreement, and elaborated turn-taking patterns due to
uncertainties were noticeable features in the complex decisions. Uncertainty was expressed using
hedges and hesitation, while silences and pauses were a trigger that led to more rationale to back
up decisions and show that a decision was not collectively agreed upon.
The findings also show that DM as a genre is in its essence a transactional interaction that,
however, much depends on relational work to execute it. Unambiguous decisions were short and
straightforward and were almost exclusively conducted through English as the medium of PMC.
In contrast, complex decisions relied heavily on discursive resources like code-switching (CS)
and humour. The function of Arabic in CS and humour included getting specific details about
patient status, defending doctors' professional image, building and maintaining solidarity and
harmony, and expressing negative emotions such as stress and anger while under pressure to reach
a decision.
This study makes the following contributions. First, it provides an authentic representation of DM
as an interactional genre in teams and reveals how hierarchical and epistemic status has influenced
this genre. In the studied context, consultants had higher authority in determining the decision and
action plan based on their epistemic status, while assistant consultants contributed by supplying
the medical information needed to aid the DM process. This shows that while the decision must
be made collaboratively, the collaboration had limits. This calls for caution in ensuring that
practicing medical professionals are aware of their roles in DM while ensuring that everyone has
a voice in the DM negotiations. Hierarchy, epistemic status, and primacy are part of this
asymmetrical interaction and guide different team members to operate and interact within the
limits and boundaries of their roles. This helps provide structure and organization and offers
guidelines on how medical professional should interact with each other.
Another contribution is addressing the gap in the English medical textbooks used to teach medical
students in Saudi Arabia. The data revealed a mismatch between the spoken interaction in the
textbooks and real-life interactions. For instance, humour and CS are not part of the textbook
materials, which does not aid in preparing medical students for the real interactional demands of
the workplace. The study also highlights some limitations of using English as a medium of
professional communication and calls for further research that takes into account the cultural
effects of the context especially regarding multilingual and multicultural membership. It is
important to understand how this diversity influences how medical professionals interact and
make decisions, especially when they must do so collaboratively
Trait macroevolution in the presence of covariates
Get PDFStatistical characterisations of traits evolving on phylogenies combine the contributions of unique and shared influences on those traits, potentially confusing the interpretation of historical events of macroevolution. The Fabric model, introduced in 2022, identifies historical events of directional shifts in traits (e.g. becoming larger/smaller, faster/slower over evolutionary time) and of changes in macroevolutionary ‘evolvability’ or the realised historical ability of a trait to explore its trait-space. Here we extend the model to accommodate situations in which the trait is correlated with one or more covarying traits. The Fabric-regression model identifies a unique component of variance in the trait that is free of influences from correlated traits, while simultaneously estimating directional and evolvability effects. We show in a dataset of 1504 Mammalian species that inferences about historical directional shifts in brain size and in its evolvability, having accounted for body size, differ qualitatively from inferences about brain size alone, including finding many new effects not visible in the whole trait. A class of fundamental macroevolutionary questions awaits testing on the variation uniquely attributable to traits, and the ability to accommodate statistically one or more covariates opens the possibility of bringing the formal methods of causal inference to phylogenetic-comparative studies
The international law obligation of states to stop intelligence support for U.S. boat strikes
No full textUnderstanding space enactment under changing scenarios: a socio-material perspective
No full textBuilding adaptation has traditionally focused on design-stage improvements to physical
attributes, overlooking the complex socio-material processes through which spatial changes
unfold after construction. This research reconceptualises building adaptation as ‘space
enactment’—examining how heterogeneous networks of human and non-human actors
participate in ongoing spatial transformation, particularly in public buildings where diverse
users engage in varied adaptation practices with different capacities for implementing
changes. Mobilising Actor-Network Theory’s (ANT) socio-material lens, this study
employed ethnographic observation and semi-structured interviews to investigate space
enactment processes in a public building. Three scenarios emerged from the data: daily,
planned, and emergency adaptations, each demonstrating different networking features. The
research followed actors through these processes, using ANT’s four moments of translation—
problematisation, interessement, enrolment, and mobilisation—to analyse how networks
form, stabilise, or fail across different scenarios. The findings reveal that human actors
perform shifting roles as initiator, approver, assessor, executor, and installer within dynamic
networks, whilst non-human actors participate actively through informational (notices),
configurational (facilities), and procedural mechanisms. The analysis demonstrates how
power emerges relationally through networking processes rather than being possessed by
individual actors, with different scenarios generating distinct translation dynamics whilst
sharing common networking principles. This research contributes a fundamental
reconceptualisation of space enactment as continuous socio-material becoming rather than
discrete interventions, providing new analytical frameworks for understanding spatial
transformation in organisational contexts whilst advancing building studies and sociomaterial literature
Ethnic minority agency in mainstream education: a regional perspective on a national challenge
No full textDo all job changes increase wellbeing?
Get PDFWe provide a comprehensive framework, based on person-environment fit, for evaluating the relationship between types of job change and wellbeing, and estimate it using fixed-effects methods applied to UK longitudinal data. Changing job is associated with large swings in job satisfaction, but not all job changes are equal. Changes in workplace are associated with increased job satisfaction only when they are associated with a change in job role. The largest associations are for changing employers. These associations extend beyond job satisfaction to mental health and, to a lesser extent, life satisfaction. Changes in broader wellbeing are especially pronounced for women
Working from paradise? An analysis of the representation of digital nomads’ values and lifestyle on Instagram
Get PDFDigital nomads (DNS) are highly mobile professionals who work while traveling and travel while working. Their lifestyle has gained increasing academic attention, also from a communication perspective. Despite initial work on the topic, little is known about the self-presentation practices of DNs on social media. To address this lack of evidence and focusing on Instagram as a key platform for this group, we adopt a Goffmanian perspective. By using semi-structured interviews, we provide an in-depth analysis of their self-presentational practices, specifically their content strategies, imagined audience, and use of platform affordances. The interviews included photo elicitation as a central element. The findings show how DNs highlight independence and freedom, de-emphasize work in favour of leisure and travel, develop audience management strategies that are mindful of the imagined audiences’ situation, while trying to foster reliability and authenticity and greatly value the flexibility and ephemerality of the Stories feature