16 | New Scientist | 9 April 2022
HealthHolograms could
help spot urinary
tract infectionsANALYSING urine using holograms
could lead to faster diagnoses for
urinary tract infections (UTIs).
The most common urine tests
have been in use for decades,
but they may lack sensitivity,
which can be a problem given that
people with UTIs might drink water
to ease their symptoms and so
produce highly diluted urine.
Nicholas Durr at Johns Hopkins
University in Maryland and hiscolleagues designed a sensitive
alternative that takes a urine
sample and produces a hologram –
a 3D representation of an object
based on detailed information
from light it interacts with.
Durr and his team passed laser
light through a sample of urine
that had been embedded in a
jelly-like substance to immobilise
the floating particles it contained,
then recorded the resulting pattern
of light with a camera.
“We record more information
than you do with a normal camera,”
says Durr. “That extra information
allows us to know about thethree-dimensional object.”
Once the light has been captured,
it is reconstructed into a 3D image
from which it is possible to identify
microscopic objects, such as cells,
within the urine sample.
The system performed differently
depending on the size of the objects
it was measuring. For relatively
large ones, such as red blood cells, it
performed well enough to suggest it
could have applications monitoringblood in urine. Bacteria, however,
are similar in size to the camera’s
pixels, so it is harder to resolve
particular types of bacteria within
the urine and prescribe the correct
antibiotic – although the system
can measure overall bacterial
concentrations in urine effectively
(arxiv.org/abs/2203.09999).
“Even if [someone] has been
drinking 2 litres of water before
a test, [Durr’s team] can crank
through very large volumes
and still get meaningful results,”
says Jennifer Rohn at University
College London. ❚
Alex Wilkins“Even if someone has been
drinking 2 litres of water,
the system can still get
meaningful results”IF LAND is used to grow plants
for bioenergy, it can’t be used
to grow food or carbon-storing
forests, nor can it provide a
habitat for wildlife. The European
Union’s proposed plan to reach
net-zero carbon emissions fails
to take account of this, meaning
it could have unintended and
undesirable consequences, such
as increasing global deforestation
and reducing biodiversity,
according to a new analysis.
“The plans assume that
converting land to energy use
has no cost, which is pretty
amazing given the context we
are in, where we are massively
clearing more land to produce
more food and where climate
strategies require that we reforest
land,” says Tim Searchinger at
Princeton University.
The EU has committed itself
to achieving “climate neutrality”
by 2050. As an intermediate step,
it is aiming to reduce emissions by
55 per cent by 2030. Last year, the
European Commission unveiled
a package of proposed laws,
called “Fit for 55”, to achieve this.
The stated aims of Fit for 55include storing more carbon in
forests and restoring biodiversity.
However, the proposed measures
would increase bioenergy use
in the EU – whose main source
of^ “renewable” energy is
already bioenergy.
Modelling by the European
Commission has estimated that
the plans would require 22 million
hectares of land to be devoted to
energy crops, equivalent to a fifthof the EU’s cropland today, says
Searchinger. It also estimates
that at least 10 million hectares
of semi-natural grasslands will
have to be converted to growing
energy crops or to highly
managed forests. What’s more,
Searchinger thinks this modelling
underestimates the amount
of land required.
The overall effect would be to
greatly increase the EU’s global
land footprint – the area of land
required to grow its food, energy
crops and wood – leading to more
deforestation and biodiversityloss. To meet climate goals, it is
essential to reduce land footprints,
says Searchinger. “If Europe
increases its land footprint,
we’re in really bad shape.”
By importing more food and
wood from other countries, the
EU will still be able to claim it is
storing more carbon in its own
forests. In fact, the EU is already
burning wood from other
countries and claiming it as a
reduction in carbon emissions.
Searchinger and his team have
calculated that by reducing biofuel
usage to 2010 levels and boosting
yields, Europe could free up
16.5 million hectares of land for
growing carbon-storing forests
and restoring biodiversity.
“In general, Fit for 55 does
have lots of positive aspects,”
says Jan Rosenow at the non-
profit Regulatory Assistance
Project. But he agrees that it
relies too heavily on bioenergy.
A spokesperson for the
European Commission said it
doesn’t comment on documents
that haven’t yet been published,
despite New Scientist supplying
an advance copy of the analysis. ❚Michael Le PageRONI^
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IMAG
ESClimate changeEU’s net-zero plan has a huge flaw
The bloc’s proposals for reducing emissions could lead to more deforestation
The EU aims to store
more carbon in forests,
like this one in FinlandNews